JDBCConnection-methods {RJDBC}

R Documentation

Methods for the class ‘JDBCConnect’ in Package ‘RJDBC’

Description

Methods for the class ‘JDBCConnection’ in Package ‘RJDBC’.

dbSendQuery and dbSendUpdate submit a SQL query to the database. The difference between the two is only that dbSendUpdate is used with DBML queries and thus doesn't return any result set.

dbGetTables and dbGetFields are similar to dbListTables and dbListFields but the result is a data frame with all available details (whereas the latter return only a character vector of the names).

Usage

dbSendUpdate (conn, statement, ...)
dbGetTables (conn, ...)
dbGetFields (conn, ...)

Arguments

conn	connection object
statement	SQL statement to execute
...	additional arguments to prepared statement substituted for "?"

Details

Some notable enhancements to the DBI API:

dbSendUpdate supports vectorized arguments which is far more efficient than using scalar updates. Example: dbSendUpdate(c, "INSERT INTO myTable VALUES(?, ?)", rnorm(1000), runif(1000)) performs a single JDBC batchExecute() call. Additional parameter max.batch=10000L is an integer that specifies the maximum batch size supported by the DBMS.

dbSendQuery and dbSendUpdate accept both ... (populated frist) as well as list= (populated as second). Only unnamed arguments are used from ... (assuming that those are function arguments and no data) while all elements are used from list=.

dbGetQuery is a shorthand for sendQuery + fetch. Parameters n=-1, block=2048L and use.label=TRUE are passed through to fetch() others to dbSendQuery.

dbListTables and dbGetTables have the arguments (conn, pattern="%", schema=NULL). dbExistsTable is just a wrapper for dbGetTables.

dbWriteTable is defined as (conn, name, value, overwrite=FALSE, append=FALSE, force=FALSE, field.types=NULL, ..., max.batch=10000L) and is just a short-hand for the corresponding dbSendUpdate() statements. Since it is only a convenience wrapper, it is strongly recommended to use dbSendUpdate() in any real use-cases as you have far more control over the shape and properties of the table if you issue the CREATE TABLE statement according to your DBMS' capabilities. It is also possible to create the table with dbSendUpdate and then use dbWriteTable(..., append=TRUE) to store the data which simply constructs INSERT INTO batch-update statement run with dbSendQuery.

dbReadTable is just a shorthand for dbGetQuery(c, "SELECT * from <table>")

Methods

dbBegin

signature(conn = "JDBCConnection", ...)

dbCommit

signature(conn = "JDBCConnection", ...)

dbDataType

signature(dbObj = "JDBCConnection", obj = "ANY", ...)

dbDisconnect

signature(conn = "JDBCConnection", ...)

dbExistsTable

signature(conn = "JDBCConnection", name = "character", ...)

dbGetException

signature(conn = "JDBCConnection", ...)

dbGetFields

signature(conn = "JDBCConnection", ...)

dbGetInfo

signature(conn = "JDBCConnection", ...)

dbGetQuery

signature(conn = "JDBCConnection", statement = "character", ...)

dbGetTables

signature(conn = "JDBCConnection", ...)

dbListFields

signature(conn = "JDBCConnection", ...)

dbListResults

signature(conn = "JDBCConnection", ...)

dbListTables

signature(conn = "JDBCConnection", ...)

dbReadTable

signature(conn = "JDBCConnection", ...)

dbRemoveTable

signature(conn = "JDBCConnection", ...)

dbRollback

signature(conn = "JDBCConnection", ...)

dbSendQuery

signature(conn = "JDBCConnection", statement = "character", ...)

dbSendUpdate

signature(conn = "JDBCConnection", statement = "character", ...)

dbWriteTable

signature(conn = "JDBCConnection", ...)

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