Oracle SQL escape character (for an '&')
Escape an &
in Oracle SQL using the concatenation (||
) operation:
Alternatively, disable substitution variables completely:
Take note, the above methods will prevent Oracle SQL from misinterpreting &
as a substitution variable prompt, enabling you to comfortably insert it into your database.
Why does &
mess with my data?
In Oracle SQL, the &
character triggers the substitution variables process. Here are two workarounds to manage this quirk:
- The concatenation method utilizes
chr(38)
to output&
without inviting annoying substitution prompts:
- SET DEFINE OFF puts the substitution mechanism to sleep:
The preferred method is SET DEFINE OFF for managing multiple ampersand encounters in your SQL scripts.
Seeking &
asylum - Alternatives and precautions
Swap the suspect
By resetting the substitution character using SET DEFINE, you can prevent disruption when switching off is not an option:
Don't forget, SET DEFINE has a scope and can trickle down to subsequent SQL statements in your script. Tread cautiously.
&
cross-dressers in SQL Developer
SQL Developer isn't a fan of escape characters like \
. It does, however, fancy other getups like 'amp;'
:
Reverting 'amp;'
back to &
may demand extra processing while retrieving data from the database.
The hardcoded approach
In dire situations, hardcoded values can help steer clear of escape character issues:
Application code string builders can incorporate special characters without sparking any SQL alerts.
Decoding the &
mysteries
User input in dynamic SQL
Suppress prompts in dynamic SQL or user inputs by pre-processing the input to replace &
with chr(38)
. Kindly note, such a tactic works without meddling with the session settings:
Sticky substitution variables
If SET DEFINE OFF doesn't persist, always renew it at the beginning of every procedure or consider running scripts where it reigns supreme as a default setting.
Playing safe with functions and procedures
While chalk and cheese, make sure the &
character in your function or procedure definitions is handled properly if these blocks pack static SQL statements containing ampersands:
Always run your tests, validate them and ensure that the logic does not alter the intended meaning of your PL/SQL art.
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