17.05 - Example: Using the DEFAULT Function With INSERT … SELECT - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL Data Manipulation Language

Product
Advanced SQL Engine
Teradata Database
Release Number
17.05
Published
January 2021
Language
English (United States)
Last Update
2021-01-22
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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.