Example: Using the DEFAULT Function With INSERT … SELECT - Teradata Database

Example: Using the DEFAULT Function With INSERT … SELECT

Assume the following table definitions for this example:

     CREATE TABLE tbl_source (

       col1 INTEGER, 

       col2 INTEGER DEFAULT 10,

       col3 INTEGER DEFAULT 20,

       col4 CHARACTER(60));

     CREATE TABLE tbl_destination (

       col1 INTEGER, 

       col2 INTEGER DEFAULT 10,

       col3 INTEGER DEFAULT 20,

       col4 CHARACTER(60));     

The following example shows correct use of the DEFAULT function within an INSERT … SELECT request:

     INSERT INTO tbl_destination (col1) 

     SELECT COALESCE(col3, DEFAULT(col3)) END 

     FROM tbl_source 

     WHERE col3 <> DEFAULT;

In this example, the DEFAULT function evaluates to a constant value, which is the default value of col3 of tbl_source.