Class ExtDriver

Description

An Oracle extproc driver class implementing the R database interface (DBI) API.

Generators

The main generators are dbDriver and Extproc.

Extends

Class "DBIDriver", directly. Class "DBIObject", by class "DBIDriver", distance 2.

Methods

dbConnect

signature(drv = "ExtDriver"): ...

dbGetInfo

signature(dbObj = "ExtDriver"): ...

dbListConnections

signature(drv = "ExtDriver"): ...

dbUnloadDriver

signature(drv = "ExtDriver"): ...

summary

signature(object = "ExtDriver"): ...

show

signature(object = "ExtDriver")

See Also

DBI classes: OraConnection-class OraResult-class

Examples

## Not run: 
con <- dbConnect(Extproc())

## End(Not run)

Class OraConnection

Description

An Oracle connection class implementing the R database interface (DBI) API.

Generators

The method dbConnect is the main generator.

Extends

Class "DBIConnection", directly. Class "DBIObject", by class "DBIConnection", distance 2.

Methods

dbDisconnect

signature(conn = "OraConnection"): ...

dbSendQuery

signature(conn = "OraConnection", statement = "character", prefetch = FALSE, bulk_read = 1000L, bulk_write = 1000L): ...

dbGetQuery

signature(conn = "OraConnection", statement = "character", prefetch = FALSE, bulk_read = 1000L, bulk_write = 1000L): ...

dbGetException

signature(conn = "OraConnection"): ...

dbListResults

signature(conn = "OraConnection"): ...

dbListTables

signature(conn = "OraConnection"): ...

dbReadTable

signature(conn = "OraConnection", name = "character"): ...

dbWriteTable

signature(conn = "OraConnection", name = "character", value = "data.frame"): ...

dbExistsTable

signature(conn = "OraConnection", name = "character"): ...

dbRemoveTable

signature(conn = "OraConnection", name = "character"): ...

dbListFields

signature(conn = "OraConnection", name = "character"): ...

dbCommit

signature(conn = "OraConnection"): ...

dbRollback

signature(conn = "OraConnection"): ...

dbGetInfo

signature(dbObj = "OraConnection"): ...

summary

signature(object = "OraConnection"): ...

show

signature(object = "OraConnection")

See Also

DBI classes: OraDriver-class OraConnection-class OraResult-class

Examples

## Not run: 
ora <- dbDriver("Oracle")
## connecting without a connect string
con <- dbConnect(ora, "scott", "tiger")

## connecting with a connection string with SID
host <- "myhost"
port <- 1521
sid <- "mysid"
connect.string <- paste(
  "(DESCRIPTION=",
  "(ADDRESS=(PROTOCOL=tcp)(HOST=", host, ")(PORT=", port, "))",
  "(CONNECT_DATA=(SID=", sid, ")))", sep = "")

## use username/password authentication
con <- dbConnect(drv, username = "scott", password = "tiger",
                 dbname = connect.string)

## connecting with a connection string with service name
host <- "myhost"
port <- 1521
svc <- "mydb.example.com"
connect.string <- paste(
  "(DESCRIPTION=",
  "(ADDRESS=(PROTOCOL=tcp)(HOST=", host, ")(PORT=", port, "))",
  "(CONNECT_DATA=(SERVICE_NAME=", svc, ")))", sep = "")
## use username/password authentication
con <- dbConnect(drv, username = "scott", password = "tiger",
                 dbname = connect.string)

## Please refer to "Oracle Database Net Services Administator's Guide", which
## has the topic "Connect Identifier and Connect Descriptor Syntax
## Characteristics"

dbListTables(con)

## End(Not run)

Class OraDriver

Description

An Oracle driver class implementing the R database interface (DBI) API.

Generators

The main generators are dbDriver and Oracle.

Extends

Class "DBIDriver", directly. Class "DBIObject", by class "DBIDriver", distance 2.

Methods

dbConnect

signature(drv = "OraDriver"): ...

dbGetInfo

signature(dbObj = "OraDriver"): ...

dbListConnections

signature(drv = "OraDriver"): ...

dbUnloadDriver

signature(drv = "OraDriver"): ...

summary

signature(object = "OraDriver"): ...

show

signature(object = "OraDriver")

See Also

DBI classes: OraConnection-class OraResult-class

Examples

## Not run: 
# first load the library
library("ROracle")
ora <- dbDriver("Oracle")
con <- dbConnect(ora, "scott", "tiger")

## End(Not run)

Class OraResult

Description

An Oracle query results class. This class encapsulates the result of a SQL statement.

Generators

The main generator is dbSendQuery.

Extends

Class "DBIResult", directly. Class "DBIObject", by class "DBIResult", distance 2.

Methods

dbClearResult

signature(res = "OraResult"): ...

dbColumnInfo

signature(res = "OraResult"): ...

dbGetInfo

signature(dbObj = "OraResult"): ...

dbGetStatement

signature(res = "OraResult"): ...

dbGetRowCount

signature(res = "OraResult"): ...

dbGetRowsAffected

signature(res = "OraResult"): ...

dbHasCompleted

signature(res = "OraResult"): ...

fetch

signature(res = "OraResult", n = "numeric"): ...

fetch

signature(res = "OraResult", n = "missing"): ...

execute

signature(res = "OraResult"): ...

summary

signature(object = "OraResult"): ...

show

signature(object = "OraResult")

See Also

DBI classes: OraDriver-class OraConnection-class OraResult-class

Examples

## Not run: 
ora <- dbDriver("Oracle")
con <- dbConnect(ora, "scott", "tiger")
res <- dbSendQuery(con, "select * from emp")
fetch(res, n = 2)
fetch(res)
dbColumnInfo(res)
dbClearResult(res)

## End(Not run)

Instantiate an Oracle client from the current R session

Description

This function creates and initializes an Oracle client from the current R session. It returns an object that allows you to connect to one or more Oracle servers.

Usage

  Oracle(interruptible = FALSE, unicode_as_utf8 = TRUE,
         ora.attributes = FALSE)
  Extproc(extproc.ctx = NULL)

Arguments

Details

This object is a singleton, that is, on subsequent invocations it returns the same initialized object.

This implementation allows you to connect to multiple host servers and run multiple connections on each server simultaneously.

When interruptible is set to TRUE, it allows for interrupting long-running queries on the server by executing the query in a thread. Main thread checks for Ctrl-C and issues OCIBreak/OCIReset to cancel the operation on the server. By default interruptible is FALSE.

When unicode_as_utf8 is set to FALSE, NCHAR, NVARCHAR and NCLOB data is fetched using the character set using the NLS_LANG setting. By default unicode_as_utf8 is set to TRUE.

When ora.attributes is set to TRUE attributes ora.encoding, ora.type and ora.maxlength are added in result data frame returned from dbGetQuery and fetch. It should be used with dbWriteTable to create the same data types as in the Oracle DBMS as fetched from the source table.

Value

An object of class OraDriver for Oracle or ExtDriver for Extproc whose class extends DBIDriver. This object is used to create connections, using the function dbConnect, to one or more Oracle database engines.

Side Effects

The R client part of the database communication is initialized, but note that connecting to the database engine needs to be done through calls to dbConnect.

Oracle user authentication

In order to establish a connection to an Oracle server users need to provide a user name, a password, and possibly a connect identifier (for more information refer to chapter 8 (Configuring Naming Methods) of Oracle Database Net Services Administrator's Guide). This is the same as the part of the SQL*Plus connect string that follows the '@' sign.

Connections to an Oracle TimesTen IMDB instance are established using the OCI tnsnames or easy connect naming methods. For additional information on TimesTen connections for OCI see chapter 3 (TimesTen Support for Oracle Call Interface) of the Oracle TimesTen In-Memory C Developer's Guide.

Transactions

The current implementation directly supports transaction commits and rollbacks on a connection-wide basis through calls to dbCommit and dbRollback. Save points are not yet directly implemented, but you may be able to define them and rollback to them through calls to dynamic SQL with dbGetQuery.

Notice that Oracle (and ANSI/ISO compliant DBMS) transactions are implicitly started when data definition SQL statements are executed (create table, etc.), which helper functions like dbWriteTable may execute behind the scenes. You may want or need to commit or roll back your work before issuing any of these helper functions.

References

For Oracle Database documentation, see http://docs.oracle.com/en/database/.

Author(s)

David A. James and Denis Mukhin

See Also

On database managers:

dbDriver dbUnloadDriver dbListConnections

On connections:

dbConnect dbDisconnect dbSendQuery dbGetQuery dbGetException dbListResults

Convenience methods: dbListTables dbReadTable dbWriteTable dbExistsTable dbRemoveTable dbListFields

On transaction management:

dbCommit dbRollback

On queries and result objects:

fetch dbClearResult dbColumnInfo dbGetStatement dbHasCompleted dbGetRowsAffected dbGetRowCount

On meta-data:

show summary dbGetInfo

Examples

  ## Not run: 
    ## create a Oracle instance and create one connection.
    ora <- Oracle()         ## or dbDriver("Oracle")
    con <- dbConnect(ora, username = "scott", password = "tiger", 
                     dbname = "inst1")

    ## if you are connecting to a local database
    con <- dbConnect(ora, username = "scott", password = "tiger")

    ## execute a statement and fetch its output in chunks of no more
    ## than 5000 rows at a time
    rs   <- dbSendQuery(con, "select * from emp where deptno = 10")
    while (!dbHasCompleted(rs)) {
      df <- fetch(rs, n = 5000)
      ## process df
    }
    dbClearResult(rs)       ## done with this query

    ## execute and fetch a statement with bind data
    df <- dbGetQuery(con, "select * from emp where deptno = :1",
                     data = data.frame(depno = 10))

    ## create a copy of emp table
    dbGetQuery(con, "create table foo as select * from emp")

    ## execute and bind an INSERT statement
    my.data = data.frame(empno = c(8001, 8002), ename = c('MUKHIN', 'ABOYOUN'))
    more.data = data.frame(empno = c(8003), ename = c('JAMES'))
    rs <- dbSendQuery(con, "insert into foo (empno, ename) values (:1, :2)",
                      data = my.data)

    ## execute with more data
    execute(rs, data = more.data)
    dbClearResult(rs)       ## done with this query

    ## ok, everything looks fine
    dbCommit(con)           

    ## a concise description of the driver 
    summary(ora)

    ## done with this connection
    dbDisconnect(con)
  
## End(Not run)

DBMS Transaction Management

Description

Commits or roll backs the current transaction in an Oracle connection

Usage

## S4 method for signature 'OraConnection'
dbCommit(conn, ...)
## S4 method for signature 'OraConnection'
dbRollback(conn, ...)

Arguments

Details

dbCommit

implementation saves all changes done on that connection. Changes can not be undone once saved permanently.

dbRollback

implementation undo all chnages done after last savepoint.

Side Effects

dbCommit

saves changes permanently.

dbRollback

undo all changes done after last save point.

References

For the Oracle Database documentaion see http://www.oracle.com/technetwork/indexes/documentation/index.html.

See Also

Oracle, dbConnect, dbSendQuery, dbGetQuery, fetch, dbCommit, dbGetInfo, dbReadTable.

Examples

  ## Not run: 
    drv <- dbDriver("Oracle")
    con <- dbConnect(drv, "scott", "tiger")
    dbReadTable(con, "EMP")
    rs <- dbSendQuery(con, "delete from emp where deptno = 10")
    dbReadTable(con, "EMP")
    if(dbGetInfo(rs, what = "rowsAffected") > 1)
    {
      warning("dubious deletion -- rolling back transaction")
      dbRollback(con)
    }
    dbReadTable(con, "EMP")
  
## End(Not run)

Create a Connection Object to an Oracle DBMS

Description

These methods are straightforward implementations of the corresponding generic functions.

Usage

## S4 method for signature 'OraDriver'
dbConnect(drv, username = "", password = "", dbname = "", prefetch = FALSE,
          bulk_read = 1000L, bulk_write = 1000L, stmt_cache = 0L,
          external_credentials = FALSE, sysdba = FALSE, ...)
## S4 method for signature 'ExtDriver'
dbConnect(drv, prefetch = FALSE, bulk_read = 1000L,
          bulk_write = 1000L, stmt_cache = 0L,
          external_credentials = FALSE, sysdba = FALSE, ...)
## S4 method for signature 'OraConnection'
dbDisconnect(conn, ...)

Arguments

Details

dbConnect

This connection object is used to execute operations on the database.

When prefetch is set to TRUE, it allows the use of the OCI prefetch buffer to retrieve additional data from the server.

The bulk_read argument is used to set an integer value indicating the number of rows to fetch at a time.

The bulk_write argument is used to set an integer value indicating the number of rows to write at a time.

The stmt_cache argument is used to enable or disable the statement caching feature. Its value specifies the statement cache size.

The external_credentials argument is used to begin OCI session authenticated with external credentials on the connection.

The sysdba argument is used to begin OCI session with SYSDBA privileges on the connection.

When establishing a connection with an ExtDriver driver, none of the arguments specifying credentials are used. A connection in this mode is a singleton object, that is, all calls to dbConnect return the same connection object.

dbDisconnect

This implementation disconnects the connection between R and the database server. It frees all resources used by the connection object. It frees all result sets associated with this connection object.

Value

Side Effects

dbConnect

Establishes a connection between R and an Oracle Database server.

dbDisconnect

Frees resources used by the connection object.

References

For the Oracle Database documentation see http://www.oracle.com/technetwork/indexes/documentation/index.html.

See Also

Oracle, dbConnect, dbSendQuery, dbGetQuery, fetch, dbCommit, dbGetInfo, dbReadTable.

Examples

  ## Not run: 
    ## Create an Oracle Database instance and create one connection on the
    ## same machine.
    drv <- dbDriver("Oracle")

    ## Use username/password authentication.
    con <- dbConnect(drv, username = "scott", password = "tiger")

    ## Run a SQL statement by creating first a resultSet object.
    rs <- dbSendQuery(con, "select * from emp where deptno = 10")

    ## We now fetch records from the resultSet into a data.frame.
    data <- fetch(rs)       ## extract all rows
    dim(data)
  
## End(Not run)
  ## Not run: 
    ## Create an Oracle Database instance and create one connection to a
    ## remote database using the SID in the connect string. 
    drv <- dbDriver("Oracle")

    ## Refer to Oracle Database Net Services Administator's Guide for
    ## details on connect string specification.
    host <- "myhost"
    port <- 1521
    sid <- "mysid"
    connect.string <- paste(
      "(DESCRIPTION=",
      "(ADDRESS=(PROTOCOL=tcp)(HOST=", host, ")(PORT=", port, "))",
        "(CONNECT_DATA=(SID=", sid, ")))", sep = "")

    ## Use username/password authentication.
    con <- dbConnect(drv, username = "scott", password = "tiger",
                     dbname = connect.string)

    ## Run a SQL statement by creating first a resultSet object.
    rs <- dbSendQuery(con, "select * from emp where deptno = 10")

    ## We now fetch records from the resultSet into a data.frame.
    data <- fetch(rs)       ## extract all rows
    dim(data)
  
## End(Not run)
  ## Not run: 
    ## Create an Oracle Database instance and create one connection to a
    ## remote database using the service name.
    drv <- dbDriver("Oracle")

    ## Refer to Oracle Database Net Services Administator's Guide for
    ## details on connect string specification.

    host <- "myhost"
    port <- 1521
    svc <- "mydb.example.com"
    connect.string <- paste(
      "(DESCRIPTION=",
      "(ADDRESS=(PROTOCOL=tcp)(HOST=", host, ")(PORT=", port, "))",
      "(CONNECT_DATA=(SERVICE_NAME=", svc, ")))", sep = "")
    ## Use username/password authentication.
    con <- dbConnect(drv, username = "scott", password = "tiger",
                     dbname = connect.string)

    ## Run a SQL statement by creating first a resultSet object.
    rs <- dbSendQuery(con, "select * from emp where deptno = 10")

    ## We now fetch records from the resultSet into a data.frame.
    data <- fetch(rs)       ## extract all rows
    dim(data)
  
## End(Not run)
  ## Not run: 
    ## Create an Oracle Database instance and create one connection.
    drv <- dbDriver("Oracle")

    ## Use Oracle Wallet authentication.
    con <- dbConnect(drv, username ="", password="", 
    dbname = "<wallet_connect_string>")

    ## Run a SQL statement by creating first a resultSet object.
    rs <- dbSendQuery(con, "select * from emp where deptno = 10")

    ## We now fetch records from the resultSet into a data.frame.
    data <- fetch(rs)       ## extract all rows
    dim(data)
  
## End(Not run)
  ## Not run: 
    ## Create an Oracle Database instance and create one connection.
    drv <- dbDriver("Oracle")

    ## Connect to a TimesTen IMDB instance using the easy connect 
    ## naming method where SampleDb is a direct driver TimesTen DSN.
    con <- dbConnect(drv, username ="scott", password="tiger", 
                     dbname = "localhost/SampleDb:timesten_direct")

    ## Run a SQL statement by creating first a resultSet object.
    rs <- dbSendQuery(con, "select * from dual")

    ## We now fetch records from the resultSet into a data.frame.
    data <- fetch(rs)       ## extract all rows
    dim(data)
  
## End(Not run)
  ## Not run: 
    ## Connect to an extproc (this assumes that the driver has already
    ## been initialized in the embedded R code by passing an external
    ## pointer representing the extproc context).
    con <- dbConnect(Extproc())

    ## Run a SQL statement by creating first a resultSet object.
    rs <- dbSendQuery(con, "select * from dual")

    ## We now fetch records from the resultSet into a data.frame.
    data <- fetch(rs)       ## extract all rows
    dim(data)
  
## End(Not run)
  ## Not run: 
    ## Create an Oracle Database instance and create one connection.
    drv <- dbDriver("Oracle")

    ## Create connection with SYSDBA privileges.
    con <- dbConnect(drv, username ="scott", password="tiger",
                     sysdba = TRUE)

    ## Run a SQL statement by creating first a resultSet object.
    rs <- dbSendQuery(con, "select * from emp where deptno = 10")

    ## We now fetch records from the resultSet into a data.frame.
    data <- fetch(rs)       ## extract all rows
    dim(data)
  
## End(Not run)
  ## Not run: 
    ## Create an Oracle Database instance and create one connection.
    drv <- dbDriver("Oracle")
    
    ## Use OS authentication as an example of external authentication
    ## Make sure that databse user exist to allow an OS authentication

    ## Create connection authenticated with external credentials.
    con <- dbConnect(drv, username ="", password="",
                     external_credentials = TRUE)
    
    ## Above dbConnect() used OS credentials to connect with database.

    ## Run a SQL statement by creating first a resultSet object.
    rs <- dbSendQuery(con, "select * from emp where deptno = 10")

    ## We now fetch records from the resultSet into a data.frame.
    data <- fetch(rs)       ## extract all rows
    dim(data)
  
## End(Not run)

Oracle Implementation of the Database Interface (DBI) Classes and Drivers

Description

Oracle driver initialization and closing.

Usage

## S4 method for signature 'OraDriver'
dbUnloadDriver(drv, ...)
## S4 method for signature 'ExtDriver'
dbUnloadDriver(drv, ...)

Arguments

Details

dbDriver

This object is a singleton, that is, subsequent invocations of dbDriver return the same initialized object.

This implementation allows you to connect to multiple host servers and run multiple connections on each server simultaneously.

When interruptible is set to TRUE, it allows for interrupting long-running queries on the server by executing the query in a thread. Main thread checks for Ctrl-C and issues OCIBreak/OCIReset to cancel the operation on the server. By default, interruptible is FALSE.

When unicode_as_utf8 is set to FALSE, NCHAR, NVARCHAR and NCLOB data is fetched using the character set specified by the NLS_LANG setting. By default, unicode_as_utf8 is set to TRUE.

When ora.attributes is set to TRUE, the result set from dbGetQuery and fetch contains DBMS-specific attributes like ora.encoding, ora.type, and ora.maxlength for the corresponding column.

dbUnloadDriver

This implementation removes communication links between the R client and the database. It frees all connections and all result sets associated with those connection objects.

Value

Side Effects

dbDriver

The R client part of the database communication is initialized, but note that connecting to the database engine needs to be done through calls to dbConnect.

dbUnloadDriver

Remove the communication link between the R client and the database.

References

For Oracle Database documentation, see http://www.oracle.com/technetwork/indexes/documentation/index.html.

See Also

Oracle, dbConnect, dbSendQuery, dbGetQuery, fetch, dbCommit, dbGetInfo, dbListTables, dbReadTable.

Examples

  ## Not run: 
    # first load the library
    library("ROracle")

    # create an Oracle instance
    drv <- dbDriver("Oracle")

    con <- dbConnect(drv, "scott", "tiger")
    dbListTables(con)

    # fetch all results from the emp table
    res <- dbGetQuery(con, "select * from emp")

    # dbSendQuery can be used to fetch data in chunks 
    # as well as all of data at once
    res <- dbSendQuery(con, "select * from emp")

    # fetch all results
    fetch(res)

    # or a chunk at a time
    fetch(res, n = 5)

    # describing the schema for the emp table using dbGetInfo
    dbGetInfo(res, what = 'fields')

    # clear the result
    dbClearResult(res)

    # disconnect from the database
    dbDisconnect(con)

    # free the driver object
    dbUnloadDriver(drv)
  
## End(Not run)

Database interface Metadata

Description

These methods are straight-forward implementations of the corresponding generic functions.

Usage

## S4 method for signature 'OraDriver'
dbGetInfo(dbObj, ...)
## S4 method for signature 'ExtDriver'
dbGetInfo(dbObj, ...)
## S4 method for signature 'OraConnection'
dbGetInfo(dbObj, what, ...)
## S4 method for signature 'OraResult'
dbGetInfo(dbObj, what, ...)
## S4 method for signature 'OraResult'
dbGetStatement(res, ...)
## S4 method for signature 'OraResult'
dbGetRowCount(res, ...)
## S4 method for signature 'OraResult'
dbGetRowsAffected(res, ...)
## S4 method for signature 'OraResult'
dbColumnInfo(res, ...)
## S4 method for signature 'OraResult'
dbHasCompleted(res)

Arguments

Details

Table, schema, and column names are case sensitive, for example, table names ABC and abc are not the same. All database schema object names should not include double quotes as they are enclosed in double quotes when the corresponding SQL statement is generated.

The ROracle method dbGetInfo provides following details about the driver object:

• \$driverName The name of the driver, "Oracle (OCI)"

• \$driverVersion The version of the ROracle driver used

• \$clientVersion The version of the Oracle Client library used

• \$conTotal The number of connections instantiated by the driver

• \$conOpen The number of connections open currently

• \$interruptible TRUE when a long-running query can be interrupted

• \$unicode_as_utf8 TRUE when character data is to be fetched in UTF8 encoded format

• \$ora_attributes TRUE when each column in a result set data frame has corresponding Oracle DBMS attributes

• \$connections Information about each connection currently open, see dbGetInfo of connection object for details

The ROracle method dbGetInfo provides following the details about the connection object:

• \$username The name of the user on this connection

• \$dbname The connect alias or the connect string used

• \$serverVersion The version of the Oracle Database server

• \$serverType The value "Oracle RDBMS"

• \$resTotal The number of result sets on this connection

• \$resOpen The number of result sets open on this connection

• \$prefetch TRUE when prefetch mechanism is used to fetch data

• \$bulk_read The number of rows to fetch at a time from DBMS

• \$bulk_write The number of rows to write at a time to DBMS

• \$stmt_cache TRUE when the statement cache is used

• \$results Information about each result set currently open, see dbGetInfo of result set for details

The ROracle method dbGetInfo provides the following details about the result set object:

• \$statement SQL statement used to produce the result set object

• \$isSelect TRUE when a select statement is specified

• \$rowsAffected The number of rows affected by DML statment

• \$rowCount The number of rows in result set currently

• \$completed TRUE if there are no more rows in the result set

• \$prefetch TRUE when the prefetch mechanism used to fetch data

• \$bulk_read The number of rows to fetch at a time from DBMS

• \$bulk_write The number of rows to write at a time to DBMS

• \$fields Information about each column in the the result set, see dbColumnInfo for details

The ROracle method dbColumnInfo provides following details about each column in the result set:

• \$name The name of the column

• \$Sclass The R type of the object containing the data returned by the Oracle RDBMS

• \$type The type of column as created in Oracle RDBMS

• \$len Length of VARCHAR, CHAR and RAW column type in Oracle RDBMS. All other columns will have NA.

• \$precision The precision of number column

• \$scale The scale of number column

• \$nullOK TRUE when a NULL value can be present in the column

The example below shows the driver, connection, result set, and column information for a table containing:

   create table foo(
     a number(21),
     b number,
     c char(20),
     d varchar(300),
     e binary_double,
     f binary_float,
     g clob,
     h blob,
     i bfile,
     j date,
     m timestamp,
     n timestamp with time zone,
     o timestamp with local time zone,
     r interval day to second,
     s raw(234)
   );
 

   library(ROracle)
Loading required package: DBI
> # instantiate ROracle driver object
> drv <- Oracle()
> con <- dbConnect(drv, "scott", "tiger")
> rs <- dbSendQuery(con, "select * from foo")
> dbGetInfo(drv)
$driverName
[1] "Oracle (OCI)"

$driverVersion
[1] "1.1-12"

$clientVersion
[1] "11.2.0.4.0"

$conTotal
[1] 1

$conOpen
[1] 1

$interruptible
[1] FALSE

$unicode_as_utf8
[1] TRUE

$ora_attributes
[1] TRUE

$connections
$connections[[1]]
User name:             scott 
Connect string:         
Server version:        11.2.0.4.0 
Server type:           Oracle RDBMS 
Results processed:     1 
OCI prefetch:          FALSE 
Bulk read:             1000 
Bulk write:            1000 
Statement cache size:  0 
Open results:          1 


> dbGetInfo(con)
$username
[1] "scott"

$dbname
[1] ""

$serverVersion
[1] "11.2.0.4.0"

$serverType
[1] "Oracle RDBMS"

$resTotal
[1] 1

$resOpen
[1] 1

$prefetch
[1] FALSE

$bulk_read
[1] 1000

$bulk_write
[1] 1000

$stmt_cache
[1] 0

$results
$results[[1]]
Statement:            select * from foo 
Rows affected:        0 
Row count:            0 
Select statement:     TRUE 
Statement completed:  FALSE 
OCI prefetch:         FALSE 
Bulk read:            1000 
Bulk write:           1000 


> dbGetInfo(rs)
$statement
[1] "select * from foo"

$isSelect
[1] TRUE

$rowsAffected
[1] 0

$rowCount
[1] 0

$completed
[1] FALSE

$prefetch
[1] FALSE

$bulk_read
[1] 1000

$bulk_write
[1] 1000

$fields
   name    Sclass                           type len precision scale nullOK
1     A   numeric                         NUMBER  NA        21     0   TRUE
2     B   numeric                         NUMBER  NA         0  -127   TRUE
3     C character                           CHAR  20         0     0   TRUE
4     D character                       VARCHAR2 300         0     0   TRUE
5     E   numeric                  BINARY_DOUBLE  NA         0     0   TRUE
6     F   numeric                   BINARY_FLOAT  NA         0     0   TRUE
7     G character                           CLOB  NA         0     0   TRUE
8     H       raw                           BLOB  NA         0     0   TRUE
9     I       raw                          BFILE  NA         0     0   TRUE
10    J   POSIXct                           DATE  NA         0     0   TRUE
11    M   POSIXct                      TIMESTAMP  NA         0     6   TRUE
12    N   POSIXct       TIMESTAMP WITH TIME ZONE  NA         0     6   TRUE
13    O   POSIXct TIMESTAMP WITH LOCAL TIME ZONE  NA         0     6   TRUE
14    R  difftime         INTERVAL DAY TO SECOND  NA         2     6   TRUE
15    S       raw                            RAW 234         0     0   TRUE

   

Value

Information about driver, connection or a result set object.

References

For the Oracle Database documentaion see http://www.oracle.com/technetwork/indexes/documentation/index.html.

See Also

Oracle, dbDriver, dbConnect, dbSendQuery, dbGetQuery, fetch, dbCommit, dbGetInfo, dbListTables, dbReadTable.

Examples

  ## Not run: 
    drv <- dbDriver("Oracle")
    con <- dbConnect(drv, "scott", "tiger")

    rs <- dbSendQuery(con, "select * from emp")

    # Get the SQL statement for the result set object rs
    dbGetStatement(rs)

    # Are there any more rows in result set?
    dbHasCompleted(rs)

    # Information about columns in result set rs object
    dbColumnInfo(rs)

    # DBIDriver info
    names(dbGetInfo(drv))

    # DBIConnection info
    names(dbGetInfo(con))

    # DBIResult info
    names(dbGetInfo(rs)) 
  
## End(Not run)

List items from Oracle objects

Description

These methods are straight-forward implementations of the corresponding generic functions.

Usage

## S4 method for signature 'OraDriver'
dbListConnections(drv, ...)
## S4 method for signature 'ExtDriver'
dbListConnections(drv, ...)
## S4 method for signature 'OraConnection'
dbListResults(conn, ...)

Arguments

Details

dbListConnections

implementation return a list of all associated connections. It shows information about all associated connections.

dbListResults

implementation return a list of all associated result sets. It shows information about all associated result sets.

Value

References

For the Oracle Database documentaion see http://www.oracle.com/technetwork/indexes/documentation/index.html.

See Also

Oracle, dbGetInfo, dbColumnInfo, dbDriver, dbConnect, dbSendQuery

Examples

  ## Not run: 
    drv <- dbDriver("Oracle")
    con1 <- dbConnect(drv, "scott", "tiger")
    res1 <- dbSendQuery(con1, "select * from emp where deptno = 10")
    res2 <- dbSendQuery(con1, "select * from emp where deptno = 20")
    con2 <- dbConnect(drv, "scott", "tiger")
    res3 <- dbSendQuery(con2, "select * from dept")

    ## get all active statements
    for(con in dbListConnections(drv))
      for (res in dbListResults(con))
        print(dbGetStatement(res))
  
## End(Not run)

Convenience Functions for Manipulating DBMS Tables

Description

These functions mimic their R counterparts except that they generate code that gets remotely executed in a database engine: get, assign, exists, remove, objects, and names.

Usage

## S4 method for signature 'OraConnection,character'
dbReadTable(conn, name, schema = NULL, row.names = NULL, ...)
## S4 method for signature 'OraConnection,character,data.frame'
dbWriteTable(conn, name, value, row.names = FALSE, overwrite = FALSE,
             append = FALSE, ora.number = TRUE, schema = NULL, date = FALSE, ...)
## S4 method for signature 'OraConnection,character'
dbExistsTable(conn, name, schema = NULL, ...)
## S4 method for signature 'OraConnection,character'
dbRemoveTable(conn, name, purge = FALSE, schema = NULL, ...)
## S4 method for signature 'OraConnection'
dbListTables(conn, schema = NULL, all = FALSE, full = FALSE, ...)
## S4 method for signature 'OraConnection,character'
dbListFields(conn, name, schema = NULL, ...)

Arguments

Details

Table, schema, and column names are case sensitive, e.g., table names ABC and abc are not the same. All database schema object names should not include double quotes as they are enclosed in double quotes when the corresponding SQL statement is generated.

The following attributes are used for mapping BLOB, CLOB, NCLOB, NCHAR, VARCHAR2, NVARCHAR2, CHAR, TIMESTAMP WITH TIME ZONE and TIMESTAMP WITH LOCAL TIME ZONE columns correctly in dbWriteTable: 1) Attribute Name: ora.type This attribute indicates the type of the underlying column and can be "CLOB", "BLOB", "CHAR", "VARCHAR2", or "RAW". The user can specify TIMESTAMP, DATE, TIMESTAMP WITH TIME ZONE or any other column types supported by Oracle Database. ROacle does not parse the value; it is validated by the database. The user can provide one of the following values for ora.type: CLOB, BLOB, CHAR, TIMESTAMP WITH TIME ZONE, TIMESTAMP WITH LOCAL TIME ZONE and fractional_seconds_precision. 2) Attribute Name: ora.encoding When UTF-8 is specified, the database uses NCLOB, NCHAR or NVARCHAR based on ora.type. 3) Attribute Name: ora.maxlength One can specify the maximum length of CHAR, VARCHAR, NCHAR, NVARCHAR2, or RAW columns. For other data types, ora.maxlength does not apply and is ignored. The following default values are used for certain data types when ora.maxlength is not specified. CHAR 2000 NCHAR 1000 VARCHAR2 4000 NVARCHAR2 2000 RAW 2000 4) Attribute Name: ora.fractional_seconds_precision One can specify the fractional part of the SECOND datetime field of TIMESTAMP, TIMESTAMP WITH TIME ZONE and TIMESTAMP WITH LOCAL TIME ZONE columns. It can be a number in the range 0 to 9. The default value is 6.

ROracle methods such as dbReadTable, dbGetQuery, fetch, and dbWriteTable use the following mapping between R and Oracle data types:

• logical and integer map to Oracle INTEGER

• numeric maps to Oracle NUMBER if argument ora.number is TRUE or Oracle BINARY_DOUBLE if FALSE

• character maps to Oracle CLOB if attribute ora.type is "CLOB" or Oracle NCLOB if attribute ora.type is "CLOB" and ora.encoding is "UTF-8" or Oracle CHAR(ora.maxlength) if attribute ora.type is "CHAR" or Oracle NCHAR(ora.maxlength) if attribute ora.type is "CHAR" and ora.encoding is "UTF-8" or Oracle NVARCHAR2(ora.maxlength) if attribute ora.encoding is "UTF-8" or Oracle VARCHAR2(ora.maxlength)

• Date and POSIXct map to Oracle DATE ROracle - the ROracle package R - the R application

• POSIXct maps to Oracle TIMESTAMP WITH TIME ZONE(ora.fractional_seconds_precision) if attribute ora.type is "TIMESTAMP WITH TIME ZONE" or Oracle TIMESTAMP WITH LOCAL TIME ZONE(ora.fractional_seconds_precision) if attribute ora.type is "TIMESTAMP WITH LOCAL TIME ZONE" or Oracle TIMESTAMP(ora.fractional_seconds_precision) and if Date is FALSE

• difftime maps to Oracle INTERVAL DAY TO SECOND

• list of raw vectors map to Oracle BLOB if attribute ora.type is "BLOB" or Oracle RAW(ora.maxlength)

• other R types such as factor are converted to character

ROracle returns values from database columns that are of data type: date, time stamp, time stamp with time zone and time stamp with local time zone data types in R's POSIXct format. POSIXct refers to a time that is internally stored as the number of seconds since the start of 1970 in UTC. Number of seconds are exchanged from R and ROracle driver in floating point double format. In POSIXct representation R uses the TZ environment variable or maps the OS time zone environment variable to its own, therefore the date will be displayed in this time zone format.

One can insert data into columns of the four data types listed above using a string with the correct format or POSIXct representation. String data is passed to the database directly and ROracle relies on databse to convert it to date time representation. ROracle driver converts the POSIXct representation to a string representation using the format "%Y-%m-%d %H:%M:%OS6" in a data frame that is used for DML operations. Data in this format corresponds to NLS_TIMESTAMP_TZ_FORMAT "YYYY-MM-DD HH24:MI:SSXFF" and is converted to SQLT_TIMESTAMP_LTZ to be bound to the Oracle database. An intermediate class "datetime" is created that represents character data to the ROracle driver internally.

Columns having a date and time stamp data type are fetched by ROracle using the SQLT_TIMESTAMP data type. Columns having a time stamp with time zone or a time stamp with local time zone data types are fetched using SQLT_TIMESTAMP_LTZ data type. Columns of data type time stamp with local time zone undergo conversion to the session time zone that the R application runs in, therefore setting the time zone environment TZ in R will affect the data values in this column. ROracle driver maps the TZ environment variable to the session time zone and issues an alter DDL to set the session time zone when the connection is made to the database.

To fetch data from columns with a timestamp with time zone or a timestamp with local time zone, the client and server must have the same time zone data file else an error will be reported.

When these data types are selected from the database, they are converted to string representation using the NLS_TIMESTAMP_TZ_FORMAT "YYYY-MM-DD HH24:MI:SSXFF" that corresponds to "%Y-%m-%d %H:%M:%OS6" in R. An intermediate class "datetime" is created to represent this character data in ROracle driver. ROracle driver then converts it to POSIXct using the as.POSIXct() function. An R application sees the data in POSIXct form in the data frame.

R session time zone:
 R has the concept of a time zone in which the R engine operates. The time
 zone can be set to a string such as 'PST8PDT', 'America/Los_Angeles' and so on.
 These strings are self-explanatory and specify the time zone in which the
 session is operating.
 The R session time zone can be set in one of two ways:
 1. By entering the following on the Linux or Unix command line before starting
    R:
    setenv TZ = America/Los_Angeles on Linux/UNIX
    NOTE: Do not use this option on Windows as it does not allow one to
          set Oracle compatible timezone names for the environment variable TZ.
 2. By entering the following at the R prompt:
    Sys.setenv(TZ = "PST8PDT")

 We recommend using the option 2 as the R script works without any
 porting issues on Linux/Unix as well as Windows. Option 2 also allows you
 to specify Oracle compatible timezone names even on Windows.

 The R session time zone determines the time zone for all POSIXct time
 zone unqualified date-time types. It is also the time zone to which all
 qualified date-time types are converted when they are displayed by R.

 The following example demonstrates this.
 Sys.setenv(TZ = "PST8PDT")
 dt <- c(as.POSIXct("2010/3/13", tz = "PST8PDT"),
         as.POSIXct("2010/3/13 3:47:30.123456", tz = "PST8PDT"),
         as.POSIXct("2010/3/22", tz = "PST8PDT"),
         as.POSIXct("2010/3/22 7:02:30", tz = "PST8PDT"),
         as.POSIXct("2010/3/13"),
         as.POSIXct("2010/3/13 3:47:30.123456"),
         as.POSIXct("2010/3/22"),
         as.POSIXct("2010/3/22 7:02:30"))
 dt
 [1] "2010-03-13 00:00:00.000000 PST" "2010-03-13 03:47:30.123456 PST"
 [3] "2010-03-22 00:00:00.000000 PDT" "2010-03-22 07:02:30.000000 PDT"
 [5] "2010-03-13 00:00:00.000000 PST" "2010-03-13 03:47:30.123456 PST"
 [7] "2010-03-22 00:00:00.000000 PDT" "2010-03-22 07:02:30.000000 PDT"

Note that the unqualified timestamps are also assumed to be in the R's
session time zone when they are displayed by R. Of course, R is also smart
enough to make the determination of whether the time falls into PST or PDT
based on when US Daylight savings begins, and displays PST or PDT
accordingly.

The following example makes this more obvious.
> Sys.setenv(TZ = "EST5EDT")
> dt <- c(as.POSIXct("2010/3/13", tz = "PST8PDT"),
+         as.POSIXct("2010/3/13 3:47:30.123456", tz = "PST8PDT"),
+         as.POSIXct("2010/3/22", tz = "PST8PDT"),
+         as.POSIXct("2010/3/22 7:02:30", tz = "PST8PDT"),
+         as.POSIXct("2010/3/13"),
+         as.POSIXct("2010/3/13 3:47:30.123456"),
+         as.POSIXct("2010/3/22"),
+         as.POSIXct("2010/3/22 7:02:30"))

> dt
[1] "2010-03-13 03:00:00.000000 EST" "2010-03-13 06:47:30.123456 EST"
[3] "2010-03-22 03:00:00.000000 EDT" "2010-03-22 10:02:30.000000 EDT"
[5] "2010-03-13 00:00:00.000000 EST" "2010-03-13 03:47:30.123456 EST"
[7] "2010-03-22 00:00:00.000000 EDT" "2010-03-22 07:02:30.000000 EDT"

Note that all the time zone unqualified timestamps are assumed to be in
the session time zone. However, even the time zone qualified timestamps
are converted to session time zone and displayed. Note that all the
values are displayed by R in the R session's time zone (with the
timezone name also modified to EST or EDT to account for
daylight savings as applicable). Refer to Date-Time Classes at
http://stat.ethz.ch/R-manual/R-devel/library/base/html/DateTimeClasses.html
and timezones at:
http://stat.ethz.ch/R-manual/R-devel/library/base/html/timezones.html
for details on how R handles dates and times and time zones)
Let's take an example where we use a longer time zone name
(often referred to as an 'Olson Name') as opposed to an abbreviation.
> Sys.setenv(TZ = "America/Los_Angeles")
> dt <- c(as.POSIXct("2010/3/13", tz = "PST8PDT"),
+         as.POSIXct("2010/3/13 3:47:30.123456", tz = "PST8PDT"),
+         as.POSIXct("2010/3/22", tz = "PST8PDT"),
+         as.POSIXct("2010/3/22 7:02:30", tz = "PST8PDT"),
+         as.POSIXct("2010/3/13"),
+         as.POSIXct("2010/3/13 3:47:30.123456"),
+         as.POSIXct("2010/3/22"),
+         as.POSIXct("2010/3/22 7:02:30"))
> dt
[1] "2010-03-13 00:00:00.000000 PST" "2010-03-13 03:47:30.123456 PST"
[3] "2010-03-22 00:00:00.000000 PDT" "2010-03-22 07:02:30.000000 PDT"
[5] "2010-03-13 00:00:00.000000 PST" "2010-03-13 03:47:30.123456 PST"
[7] "2010-03-22 00:00:00.000000 PDT" "2010-03-22 07:02:30.000000 PDT"

Note that in such a case, R doesn't use the long name when the
values are displayed, but instead still displays the values using
the abbreviations "PST" and "PDT". This is significant because Oracle
doesn't necessarily like these abbreviations. For example, an Oracle
databse doesn't recognize "PDT" as a valid time zone. See "R Time zone
and Oracle session time zone" for details on valid time zones.

The example below shows the effect of changing the time zone in R environment:

   R> Sys.timezone()
   [1] "PST8PDT"
   # Selecting data and displaying it
   res <- dbGetQuery(con, selStr)
   R>     res[,1]
   [1] 1 2 3 4 5 6
   R>     res[,2]
   [1] "2012-06-05 00:00:00 PDT" "2012-01-05 07:15:02 PST"
       "2012-01-05 00:00:00 PST" "2011-01-05 00:00:00 PST"
   [5] "2013-01-05 00:00:00 PST" "2020-01-05 00:00:00 PST"
   R>     res[,3]
   [1] "2012-06-05 00:00:00 PDT" "2012-01-05 07:15:03 PST"
       "2012-01-05 00:00:00 PST" "2011-01-05 00:00:00 PST"
   [5] "2013-01-05 00:00:00 PST" "2020-01-05 00:00:00 PST"
   R>     res[,4]
   [1] "2012-06-05 00:00:00 PDT" "2012-01-05 07:15:03 PST"
       "2012-01-05 00:00:00 PST" "2011-01-05 00:00:00 PST"
   [5] "2013-01-05 00:00:00 PST" "2020-01-05 00:00:00 PST"
   R>     res[,5]
   [1] "2012-06-05 00:00:00 PDT" "2012-01-05 07:15:03 PST"
       "2012-01-05 00:00:00 PST" "2011-01-05 00:00:00 PST"
   [5] "2013-01-05 00:00:00 PST" "2020-01-05 00:00:00 PST"
   R> Sys.setenv(TZ='EST5EDT')
   R>     res[,1]
   [1] 1 2 3 4 5 6
   R>     res[,2]
   [1] "2012-06-05 03:00:00 EDT" "2012-01-05 10:15:02 EST"
       "2012-01-05 03:00:00 EST" "2011-01-05 03:00:00 EST"
   [5] "2013-01-05 03:00:00 EST" "2020-01-05 03:00:00 EST"
   R>     res[,3]
   [1] "2012-06-05 03:00:00 EDT" "2012-01-05 10:15:03 EST"
       "2012-01-05 03:00:00 EST" "2011-01-05 03:00:00 EST"
   [5] "2013-01-05 03:00:00 EST" "2020-01-05 03:00:00 EST"
   R>     res[,4]
   [1] "2012-06-05 03:00:00 EDT" "2012-01-05 10:15:03 EST"
       "2012-01-05 03:00:00 EST" "2011-01-05 03:00:00 EST"
   [5] "2013-01-05 03:00:00 EST" "2020-01-05 03:00:00 EST"
   R>     res[,5]
   [1] "2012-06-05 03:00:00 EDT" "2012-01-05 10:15:03 EST"
       "2012-01-05 03:00:00 EST" "2011-01-05 03:00:00 EST"
   [5] "2013-01-05 03:00:00 EST" "2020-01-05 03:00:00 EST"

Also dbWriteTable always auto commits a current transaction as well as the data it inserts, i.e. it acts as a DDL statement even if appends rows to an already existing table.

Value

A data.frame in the case of dbReadTable; a vector in the case of dbListTables and dbListFields; a logical in the case of dbExistsTable indicating whether the table exists; otherwise TRUE when the operation was successful or an exception.

References

For the Oracle Database documentation see http://www.oracle.com/technetwork/indexes/documentation/index.html. For Datetime Data Types and Time Zone Support in Oracle see http://docs.oracle.com/cd/E11882_01/server.112/e10729/ch4datetime.htm.

See Also

Oracle, dbDriver, dbConnect, dbSendQuery, dbGetQuery, fetch, dbCommit, dbGetInfo.

Examples

  ## Not run: 
    con <- dbConnect(Oracle(), "scott", "tiger")
    if (dbExistsTable(con, "FOO", "SCOTT"))
      dbRemoveTable(con, "FOO")

    foo <- dbReadTable(con, "EMP")
    row.names(foo) <- foo$EMPNO
    foo <- foo[,-1]

    dbWriteTable(con, "FOO", foo, row.names = TRUE)
    dbWriteTable(con, "FOO", foo, row.names = TRUE, overwrite = TRUE)
    dbReadTable(con, "FOO", row.names = 1)

    dbGetQuery(con, "delete from foo")
    dbWriteTable(con, "FOO", foo, row.names = TRUE, append = TRUE)
    dbReadTable(con, "FOO", row.names = 1)
    dbRemoveTable(con, "FOO")

    dbListTables(con)
    dbListFields(con, "EMP")

    if (dbExistsTable(con, "RORACLE_TEST", "SCOTT"))
      dbRemoveTable(con, "RORACLE_TEST")

    # Example of POSIXct usage.
    # A table is created using:
    createTab <- "create table RORACLE_TEST(row_num number, id1 date,
                 id2 timestamp, id3 timestamp with time zone, 
                 id4 timestamp with local time zone )"

    dbGetQuery(con, createTab)
    # Insert statement.
    insStr <- "insert into RORACLE_TEST values(:1, :2, :3, :4, :5)";

    # Select statement.
    selStr <- "select * from RORACLE_TEST";

    # Insert time stamp without time values in POSIXct form.
    x <- 1; 
    y <- "2012-06-05";
    y <- as.POSIXct(y);
    dbGetQuery(con, insStr, data.frame(x, y, y, y, y));

    # Insert date & times stamp with time values in POSIXct form.
    x <- 2;
    y <- "2012-01-05 07:15:02";
    y <- as.POSIXct(y);
    z <- "2012-01-05 07:15:03.123";
    z <- as.POSIXct(z);
    dbGetQuery(con, insStr, data.frame(x, y, z,  z, z));

    # Insert list of date objects in POSIXct form.
    x <- c(3, 4, 5, 6);
    y <- c('2012-01-05', '2011-01-05', '2013-01-05', '2020-01-05');
    y <- as.POSIXct(y);
    dbGetQuery(con, insStr, data.frame(x, y, y, y, y));

    dbCommit (con)

    # Selecting data and displaying it.
    res <- dbGetQuery(con, selStr)
    res[,1]
    res[,2]
    res[,3]
    res[,4]
    res[,5]

    # insert data in Date format
    a<-as.Date("2014-01-01")
    dbWriteTable(con, 'TEMP', data.frame(a), date = TRUE)

    # using attribute to map NCHAR, CLOB, BLOB, NCLOB columns correctly in 
    # dbWriteTable
    str1 <- paste(letters, collapse="")
    lstr1 <- paste(rep(str1, 200), collapse="")
    raw.lst <- vector("list",1)
    lraw.lst <- vector("list",1)
    raw.lst[[1L]] <- charToRaw(str1)
    lraw.lst[[1L]] <- rep(charToRaw(str1), 200)
    a <- as.POSIXct("2014-01-01 14:12:09.0194733")
    b <- as.POSIXct("2014-01-01 14:12:09.01947")
    test.df <- data.frame(char=str1, nchar=str1, varchar=str1, clob=lstr1,
                      nclob=lstr1, stringsAsFactors=FALSE)
    test.df$raw.typ <- raw.lst
    test.df$blob <- lraw.lst
    test.df$char_max <- str1 
    test.df$raw_max.typ <- raw.lst
    test.df$nvchar <- str1
    test.df$nvchar_max <- str1
    test.df$date_tz <- a
    test.df$date_ltz <- b

    # adding attributes
    attr(test.df$clob, "ora.type") <- "CLOB"
    attr(test.df$blob, "ora.type") <- "BLOB"
    attr(test.df$nclob, "ora.type") <- "CLOB"
    attr(test.df$nclob, "ora.encoding") <- "UTF-8"
    attr(test.df$char_max, "ora.maxlength") <- 3000
    attr(test.df$raw_max.typ, "ora.maxlength") <- 1000
    attr(test.df$nvchar, "ora.encoding") <- "UTF-8"
    attr(test.df$nvchar_max, "ora.encoding") <- "UTF-8"
    attr(test.df$nvchar_max, "ora.maxlength") <- 1500
    attr(test.df$char, "ora.type") <- "CHAR"
    attr(test.df$date_tz, "ora.type") <- "timestamp with time zone"
    attr(test.df$date_ltz, "ora.type") <- "timestamp with local time zone"
    attr(test.df$nchar, "ora.type") <- "CHAR"
    attr(test.df$nchar, "ora.encoding") <- "UTF-8"
    attr(test.df$date_tz, "ora.fractional_seconds_precision") <- 9
R> # displaying the data frame
R> test.df
char                         nchar
1 abcdefghijklmnopqrstuvwxyz abcdefghijklmnopqrstuvwxyz
varchar
1 abcdefghijklmnopqrstuvwxyz
clob
1 abcdefghijklmnopqrstuvwxyz...
nclob
1 abcdefghijklmnopqrstuvwxyz...
raw.typ
1 61, 62, 63, 64, 65, 66, 67, 68, 69, 6a, 6b, 6c, 6d, 6e, 6f, 70, 71, 72, 73,
  74, 75, 76, 77, 78, 79, 7a
blob
1 61, 62, 63, 64, 65, 66, 67, 68, 69, 6a, 6b, 6c, 6d, 6e, 6f, 70, 71, 72, 73,
  74, 75, 76, 77, 78, 79, 7a,...
char_max
1 abcdefghijklmnopqrstuvwxyz
raw_max.typ
1 61, 62, 63, 64, 65, 66, 67, 68, 69, 6a, 6b, 6c, 6d, 6e, 6f, 70, 71, 72, 73,
  74, 75, 76, 77, 78, 79, 7a
nvchar                       nvchar_max
1 abcdefghijklmnopqrstuvwxyz abcdefghijklmnopqrstuvwxyz
date_tz                      date_ltz
1 2014-01-01 14:12:09.019473 2014-01-01 14:12:09.01946

    dbWriteTable(con, name="TEST_TAB", value=test.df)
    res <- dbReadTable(con, name="TEST_TAB")
R> res
char
1 abcdefghijklmnopqrstuvwxyz
nchar
1 abcdefghijklmnopqrstuvwxyz
varchar
1 abcdefghijklmnopqrstuvwxyz
clob
1 abcdefghijklmnopqrstuvwxyz...
nclob
1 abcdefghijklmnopqrstuvwxyz...
raw.typ
1 61, 62, 63, 64, 65, 66, 67, 68, 69, 6a, 6b, 6c, 6d, 6e, 6f, 70, 71, 72, 73,
  74, 75, 76, 77, 78, 79, 7a
blob
1 61, 62, 63, 64, 65, 66, 67, 68, 69, 6a, 6b, 6c, 6d, 6e, 6f, 70, 71, 72, 73,
  74, 75, 76, 77, 78, 79, 7a,...
char_max                                                                                           
1 abcdefghijklmnopqrstuvwxyz
raw_max.typ
1 61, 62, 63, 64, 65, 66, 67, 68, 69, 6a, 6b, 6c, 6d, 6e, 6f, 70, 71, 72, 73,
  74, 75, 76, 77, 78, 79, 7a
nvchar                       nvchar_max
1 abcdefghijklmnopqrstuvwxyz abcdefghijklmnopqrstuvwxyz
date_tz                      date_ltz
1 2014-01-01 14:12:09.019473 2014-01-01 14:12:09.01946
  
## End(Not run)
  ## Not run: 
    df <- data.frame(A=c(0,1,NaN,4), B=c(NA, 2,3,NaN))
    con <- dbConnect(Oracle(), "scott", "tiger")
    dbWriteTable(con,"TEST", df, row.names = FALSE, ora.number=FALSE)
  
## End(Not run)

Execute a Statement on a Given Database Connection

Description

These methods are straight-forward implementations of the corresponding generic functions except for the execute method, which is an ROracle specific DBI extension.

Usage

## S4 method for signature 'OraConnection,character'
dbSendQuery(conn, statement, data = NULL,
          prefetch = FALSE, bulk_read = 1000L, bulk_write = 1000L, ...)
## S4 method for signature 'OraConnection,character'
dbGetQuery(conn, statement, data = NULL,
          prefetch = FALSE, bulk_read = 1000L, bulk_write = 1000L, ...)
## S4 method for signature 'OraConnection,character'
oracleProc(conn, statement, data = NULL, 
          prefetch = FALSE, bulk_read = 1000L, bulk_write = 1000L, ...)
## S4 method for signature 'OraResult'
dbClearResult(res, ...)
## S4 method for signature 'OraConnection'
dbGetException(conn, ...)

execute(res, ...)
## S4 method for signature 'OraResult'
execute(res, data = NULL, ...)

Arguments

Details

dbGetQuery

This function executes a query statement and fetches the result data from the database. It should not be used for calling PL/SQL queries.

dbSendQuery

This function executes a query statement and returns a result set to the application. The application can then perform operations on the result set. It should not be used for calling PL/SQL queries.

oracleProc

This function executes a PL/SQL stored procedure or function query statement and returns the result.

dbClearResult

This function frees resources used by result set.

dbGetException

This function retrieves error information.

execute

This function executes the specified query statement.

Value

Side Effects

dbGetQuery

Query statement is executed and data is fetched from database.

dbSendQuery

Query statement is executed, but data needs to be fetched through calls to fetch.

oracleProc

PL/SQL stored procedure or function query statement is executed and result is returned.

dbClearResult

Resources acquired by the result set are freed.

dbGetException

Error information is retrieved and then cleaned from the driver.

execute

Query statement is executed.

References

For the Oracle Database documentation see http://www.oracle.com/technetwork/indexes/documentation/index.html.

See Also

Oracle, dbDriver, dbConnect, fetch, dbCommit, dbGetInfo, dbReadTable.

Examples

  ## Not run: 
    drv <- dbDriver("Oracle")
    con <- dbConnect(drv, "scott", "tiger")
    res <- dbSendQuery(con, "select * from emp where deptno = :1",
                       data = data.frame(deptno = 10))
    data <- fetch(res, n = -1)
    res2 <- dbSendQuery(con, "select * from emp where deptno = :1",
                        data1 <- data.frame(deptno = 10), prefetch=TRUE,
                        bulk_read=2L)
    data1 <- fetch(res2, n = -1)
    data1

    res3 <- dbSendQuery(con, "select * from emp where deptno = :1",
                        data2 <- data.frame(deptno = 10), bulk_read=10L)
    data2 <- fetch(res3, n = -1)
    data2

    res4 <- dbSendQuery(con, "select * from emp where deptno = :1",
                        data3 <- data.frame(deptno = 10), bulk_write=10L)
    data3 <- fetch(res4, n = -1)
    data3

    res5 <- dbSendQuery(con, "select * from emp where ename = :1",
                        data4 <- data.frame(ename = 'SMITH')) 
    data4 <- fetch(res5, n = -1)
    data4
  
## End(Not run)

Fetch records from a previously executed query

Description

This method is a straight-forward implementation of the corresponding generic function.

Usage

## S4 method for signature 'OraResult'
fetch(res, n = -1, ...)

Arguments

Details

The ROracle implementations retrieves only n records, and if n is missing it returns all records.

Value

number of records fetched from database.

References

For the Oracle Database documentaion see http://www.oracle.com/technetwork/indexes/documentation/index.html.

See Also

Oracle, dbConnect, dbSendQuery, dbGetQuery, dbClearResult, dbCommit, dbGetInfo, dbReadTable.

Examples

  ## Not run: 
    drv <- dbDriver("Oracle")
    con <- dbConnect(drv, "scott", "tiger")
    res <- dbSendQuery(con, "select * from emp")

    # we now fetch the first 10 records from the resultSet into a data.frame
    data1 <- fetch(res, n = 10)   
    dim(data1)

    dbHasCompleted(res)

    # let's get all remaining records
    data2 <- fetch(res, n = -1)
  
## End(Not run)

Summarize an Oracle object

Description

These methods are straight-forward implementations of the corresponding generic functions.

Usage

## S4 method for signature 'OraDriver'
summary(object, ...)
## S4 method for signature 'ExtDriver'
summary(object, ...)
## S4 method for signature 'OraConnection'
summary(object, ...)
## S4 method for signature 'OraResult'
summary(object, ...)

Arguments

Value

description of object.

References

For the Oracle Database documentaion see http://www.oracle.com/technetwork/indexes/documentation/index.html.

See Also

Oracle, dbConnect, dbSendQuery, dbGetQuery, dbClearResult, dbCommit, dbGetInfo, dbGetInfo.

Examples

  ## Not run: 
    drv <- dbDriver("Oracle")
    con <- dbConnect(drv, "scott", "tiger")
    res <- dbSendQuery(con, "select * from emp")

    summary(drv)
    summary(con)
    summary(res)
    show(drv)
    show(con)
    show(res)   
  
## End(Not run)