Creating a User Defined Function using a C program - Cloud

Talend Cloud Data Management Platform Studio User Guide

EnrichVersion
Cloud
EnrichProdName
Talend Cloud
EnrichPlatform
Talend Management Console
Talend Studio
task
Design and Development
You can create a User Defined Function (UDF) function using a C program and install it on the Teradata database in order to use regular expressions.

Before you begin

  • Retrieve the Regex_INSTR.c file from the Downloads tab in the left panel of this page.

Procedure

  1. Create a C program like Regex_INSTR.c.
  2. Put this C file on your Teradata database.
  3. Login to Teradata using the user created previously.
  4. Create a UDF function. You can use the following command for example:
    CREATE FUNCTION Regex_INSTR (
    InputString VARCHAR(4096) CHARACTER SET LATIN,
    PatternString VARCHAR(512) CHARACTER SET LATIN )
    RETURNS INTEGER
    LANGUAGE C
    NO SQL
    EXTERNAL NAME 'CS!Regex_INSTR!/Regex_INSTR.c!F!Regex_INSTR1'
    PARAMETER STYLE SQL;
  5. Test the UDF using the following SQL instruction:
    select Regex_INSTR('A','[A-Z]');
    The instruction should return 1.