dbUpdateTable: update records in a database table

In schardtbc/DBIExt: Extentsion for DBI; new Generics

Description

a call to 'dbUpdateTable()' executes the sql to update records for a target database using the data in the 'data.update' data-frame. The default method provided, 4 SQL statements are generated to perform the update: a call to 'dbCreateTable()'; a call to 'dbAlterTabledatecreates and populates a temporary table using the data provided the 'data.update' dataframe

Usage

dbUpdateTable(con, target.table, data.update, set = NULL, by = NULL,
  ...)

Arguments

con	an S4 object that inherits from DBIConnection. This object is used to communicate with the database engine
target.table	A character string specifying the unquoted DBMS table name, or the result of a call to dbQuoteIdentifier().
data.update	a data.frame (or coercible to data.frame).
set	a named character vector of varibles If NULL, the default, then the function expects the data.update to be a grouped data.frame. The UPDATE statement will be constructed to match the ungrouped columns in the 'data.update' dataset with identically names columns in the target database table. If not NULL, then a character vector provides the names of the columns to join the database table to the dataframe. example by = c("symbol", "date"). Use a named vector by = c("col1" = "col2") to match columns with different names in the database target table and the supplied data.update dataset.
by	a character vector of variables to join. If NULL, the default, then the function expects the data.update to be a grouped data.frame. The grouped columns will be matched with identically named columns the database table to construct the inner join clause the the update statement. A message lists the variables so that you can check they're right (to suppress the message, simply explicitly list the variables that you want to join). If not NULL, then a character vector provides the names of the columns to join the database table to the dataframe. example by = c("symbol", "date"). Use a named vector by = c("col1" = "col2") to match columns with different names in the database target table and the supplied data.update dataset.

Details

An UPDATE statement is then constructed by the dbUpdateTable() method. The generated sql is then passed to dbExecute().

See Also

Other DBIConnection generics: dbAddIndex, dbAddPrimaryKey, dbDeleteAllRecords, dbDropTable, dbReplaceInTable

schardtbc/DBIExt documentation built on June 7, 2019, 2:39 p.m.