Example: Table Function with Fixed Result Row Specification - Analytics Database - Teradata Vantage

SQL External Routine Programming

Deployment
VantageCloud
VantageCore
Edition
Enterprise
IntelliFlex
VMware
Product
Analytics Database
Teradata Vantage
Release Number
17.20
Published
June 2022
Language
English (United States)
Last Update
2023-07-11
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iiv1628111441820.ditamap
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B035-1147
lifecycle
latest
Product Category
Teradata Vantage™

Here is an example of how to declare a table function:

/*****  C source file name: store_data.c  *****/
   
#define  SQL_TEXT Latin_Text
#include <sqltypes_td.h>
#include <string.h>
 
void get_store_data( INTEGER  *filetoread,    /* input argument  */
                     INTEGER  *storeno,       /* output argument */
                     INTEGER  *itemno,        /* output argument */
                     INTEGER  quantsold,      /* output argument */
                     int      *filetoreadIsNull,
                     int      *storenoIsNull,
                     int      *itemnoIsNull,
                     int      *quantsoldIsNull;
                     char     sqlstate[6],
                     SQL_TEXT extname[129],
                     SQL_TEXT specific_name[129],
                     SQL_TEXT error_message[257] )
{
     ...
}

The corresponding CREATE FUNCTION statement that installs the table function on the server looks like this:

CREATE FUNCTION getStoreData
  (FileToRead INTEGER)
RETURNS TABLE
   (StoreNo   INTEGER
   ,ItemNo    INTEGER
   ,QuantSold INTEGER)
LANGUAGE C
NO SQL
EXTERNAL NAME 'CS!getstoredata!udfsrc/store_data.c!F!get_store_data'
PARAMETER STYLE SQL;

Here is an example of an INSERT ... SELECT statement that invokes the table function in the FROM clause:

INSERT INTO Sales_Table
SELECT *
FROM TABLE (getStoreData(9005)) AS tf;