rxTeradataSql: rxTeradataSql

Description

Execute an arbitrary SQL statement that does not return data in a Teradata data base.

Usage

  rxTeradataSql(sqlStatement, connectionString = NULL, ...)
  rxTeradataTableExists(table, connectionString = NULL, ...)
  rxTeradataDropTable(table, connectionString = NULL, ...)

Arguments

sqlStatement

character string specifying valid SQL statement that does not return data

table

One of the following:

• a character string specifying a table name, in the form "tablename" or"database.tablename". (In Teradata, each user is a database; the user database can be specified as "username.tablename".)
• an RxTeradata data source that has the table specified
• an RxOdbcData data source that has the table specified.

connectionString

NULL or character string specifying the connection string. If NULL, the connection string from the currently active compute context will be used if available.

...

Additional arguments to be passed through.

Details

An SQL query is passed to the Teradata ODBC driver.

Value

rxTeradataSql is executed for the side effects and returns NULL invisibly. rxTeradataTableExists returns TRUE is the table exists, FALSE otherwise. The database searched for the table is determined as follows:

* If the table argument is a character string and specifies a database, that is, if the table argument is specified as "database.tablename", the specified database is searched for the table. If the containing database does not exist, an error is returned.

* If the table argument is a character string and does not specify a database, that is, if the table argument is specified as "tablename",the database specified in the connectionString is searched. If connectionString is missing, the connection string in the current compute context object is used.

* If the table argument is an RxTeradata or RxOdbcData data source, the table name specified in the data source is searched for in the database specified in the data source.

rxTeradataDropTable returns TRUE is the table is successfully dropped, FALSE otherwise (for example, if the table did not exist).

Author(s)

Microsoft Corporation Microsoft Technical Support

See Also

RxTeradata

Examples

 ## Not run:

# Copy a table
sqlStatement <- "CREATE TABLE YourDataBase.rxClaimsCopy AS YourDataBase.claims WITH DATA"
rxTeradataSql(sqlStatement = sqlStatement)

# Use the RxOdbcData data source and its sqlQuery argument to 
# get data back as a data frame:
rxTeradataQuery <- function(query, connectionString=NULL, maxRowsByCols=NULL)
{
   if (is.null(connectionString))
   {
       currentComputeContext <- rxGetComputeContext()
       if (.hasSlot(currentComputeContext, "connectionString"))
       {
           connectionString <- currentComputeContext@connectionString
       }
       else
       {
           stop("A 'connectionString' must be specified.")
       }
   }   
   internalDS <- RxOdbcData(sqlQuery=query, connectionString=connectionString)
   rxImport(internalDS, maxRowsByCols=maxRowsByCols)   
}
## Use the above to show the tables in database 'dbtest':
tableQuery <- paste("SELECT TableName FROM dbc.tables ",
                   "WHERE tablekind = 'T' and databasename='dbtest'", sep="")
rxTeradataQuery(query=tableQuery)
## End(Not run)