I currently have the query running on Postgres:
SELECT * FROM addenda.users WHERE users.username LIKE '%\_'
But rather then returning just entries ending in an underscore, I get all results back, regardless of whether it contains an underscore or not.
Running the query below returns a username which is just an underscore, so the escaping does work:
SELECT * FROM addenda.users WHERE users.username LIKE '\_'
And running the query below returns a username which ends with a specific letter (s):
SELECT * FROM addenda.users WHERE users.username LIKE '%s'
What am I doing wrong?
The LIKE operator is used in a WHERE clause to search for a specified pattern in a column. There are two wildcards often used in conjunction with the LIKE operator: The percent sign (%) represents zero, one, or multiple characters. The underscore sign (_) represents one, single character.
To broaden the selections of a structured query language (SQL-SELECT) statement, two wildcard characters, the percent sign (%) and the underscore (_), can be used.
If you are searching for an underscore then escape it with a '\' so you would search for' \_'. When matching SQL patterns, you can use these symbols as placeholders: % (percent) to substitute for zero or more characters, or _ (underscore) to substitute for one single character.
SQL Server T-SQL Wildcard Characters Unlike literal characters, wildcard characters have specific meaning for the LIKE operator. Hence, underscore ('_') in LIKE does not mean a specific regular character, but any single character.
Is your backslash not getting through to PostgreSQL? If you're passing the string through another layer that treats the backslash as an escape character (e.g. a Java String), then that layer may be removing the backslash, and you might need to escape your backslash for that layer.
Do you have any more single character usernames? If the backslash wasn't getting through to PostgreSQL then they would also match '_'
You might be able to try the ESCAPE clause: username LIKE '%!_' ESCAPE '!'
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With