Conquering the Confusion: A Guide to Using Ampersands in SQL Plus

Escape the Ampersand:

• You can escape the ampersand using a backslash (\) before it. This tells SQL Plus to interpret the ampersand literally as a character and not as a substitution variable.

SELECT * FROM table_name WHERE column_name = 'This \& That';

In this example, the ampersand in the string literal is escaped, so it will be treated as part of the string value.

Use Double Quotes:

• You can enclose your string literals in double quotes ("). Double quotes also have the effect of escaping special characters within the string, including the ampersand.

SELECT * FROM table_name WHERE column_name = 'This & That';

This approach achieves the same result as escaping with a backslash.

Disable Substitution Variables:

• You can temporarily disable substitution variables using the SET DEFINE OFF command. This will prevent SQL Plus from interpreting any ampersands as substitution variables. However, be cautious with this method, as it might affect other parts of your script that rely on substitution variables.

SET DEFINE OFF;

SELECT * FROM table_name WHERE column_name = 'This & That';

SET DEFINE ON;  -- Re-enable substitution variables if needed

Choosing the Right Method:

• If you only need to escape a few ampersands occasionally, using the backslash escape or double quotes is the recommended approach.
• If you have many ampersands throughout your script and don't rely on substitution variables, disabling them with SET DEFINE OFF can be a simpler solution. However, remember to re-enable them (SET DEFINE ON) if needed later in your script.