ASA SQL User's Guide
  Importing and Exporting Data
    Importing and exporting data

Outputting NULLs

Users often want to extract data for use in other software products. Since the other software package may not understand NULL values, there are two ways of specifying how NULL values are output. You can use either the Interactive SQL NULLS option, or the IFNULL function. Both options allow you to output a specific value in place of a NULL value.

Use the Interactive SQL NULLS option to set the default behavior, or to change the output value for a particular session. Use the IFNULL function to apply the output value to a particular instance or query.

Specifying how NULL values are output provides for greater compatibility with other software packages.

To specify NULL value output (Interactive SQL)

1. From the Interactive SQL window, choose Tools > Options to display the Options dialog.

2. Click the Results tab.

3. In the Display Null Values As field, type the value you want to replace null values with.

4. Click Make Permanent if you want the changes to become the default, or click OK if you want the changes to be in effect only for this session.

For more information on setting Interactive SQL options, see SET OPTION statement.