How can I escape square brackets in a LIKE clause?

I am trying to filter items with a stored procedure using like. The column is a varchar(15). The items I am trying to filter have square brackets in the name.

For example: WC[R]S123456.

If I do a LIKE 'WC[R]S123456' it will not return anything.

I found some information on using the ESCAPE keyword with LIKE but I do not understand how to use it to treat the square brackets as a regular string.

LIKE 'WC[[]R]S123456' 

or

LIKE 'WC\[R]S123456' ESCAPE '\'

Should work.

Let's say you want to match the literal its[brac]et.

You don't need to escape the ] as it has special meaning only when it is paired with [.

Therefore escaping [ suffices to solve the problem. You can escape [ by replacing it with [[].

I needed to exclude names that started with an underscore from a query, so I ended up with this:

WHERE b.[name] not like '\_%' escape '\'  -- use \ as the escape character

Here is what I actually used:

like 'WC![R]S123456' ESCAPE '!'

The ESCAPE keyword is used if you need to search for special characters like % and _, which are normally wild cards. If you specify ESCAPE, SQL will search literally for the characters % and _.

Here's a good article with some more examples

SELECT columns FROM table WHERE 
    column LIKE '%[[]SQL Server Driver]%' 
 
-- or 
 
SELECT columns FROM table WHERE 
    column LIKE '%\[SQL Server Driver]%' ESCAPE '\'

If you would need to escape special characters like '_' (underscore), as it was in my case, and you are not willing/not able to define an ESCAPE clause, you may wish to enclose the special character with square brackets '[' and ']'.

This explains the meaning of the "weird" string '[[]' - it just embraces the '[' character with square brackets, effectively escaping it.

My use case was to specify the name of a stored procedure with underscores in it as a filter criteria for the Profiler. So I've put string '%name[_]of[_]a[_]stored[_]procedure%' in a TextData LIKE field and it gave me trace results I wanted to achieve.

Here is a good example from the documentation: LIKE (Transact-SQL) - Using Wildcard Characters As Literals

According to documentation:

> You can use the wildcard pattern matching characters as literal > characters. To use a wildcard character as a literal character, > enclose the wildcard character in brackets.

You need to escape these three characters %_[:

'5%'      LIKE '5[%]'      -- true
'5$'      LIKE '5[%]'      -- false
'foo_bar' LIKE 'foo[_]bar' -- true
'foo$bar' LIKE 'foo[_]bar' -- false
'foo[bar' LIKE 'foo[[]bar' -- true
'foo]bar' LIKE 'foo]bar'   -- true

Instead of '' or another character on the keyboard, you can also use special characters that aren't on the keyboard. Depending o your use case this might be necessary, if you don't want user input to accidentally be used as an escape character.

There is a problem in that whilst:

LIKE 'WC[[]R]S123456' 

and:

LIKE 'WC\[R]S123456' ESCAPE '\'

Both work for SQL Server but neither work for Oracle.

It seems that there is no ISO/IEC 9075 way to recognize a pattern involving a left brace.

Use Following.

For user input to search as it is, use escape, in that it will require following replacement for all special characters (below covers all of SQL Server).

Here single quote "'" is not taken as it does not affect like clause as It is a matter of string concatenation.

"-" & "^" & "]" replace is not required as we are escaping "[".

String FormattedString = "UserString".Replace("ð","ðð").Replace("_", "ð_").Replace("%", "ð%").Replace("[", "ð[");

Then, in SQL Query it should be as following. (In parameterised query, string can be added with patterns after above replacement).

To search exact string.

like 'FormattedString' ESCAPE 'ð'

To search start with string

like '%FormattedString' ESCAPE 'ð'

To search end with string

like 'FormattedString%' ESCAPE 'ð'

To search contain with string

like '%FormattedString%' ESCAPE 'ð'

and so on for other pattern matching. But direct user input needs to format as mentioned above.