LIKE Command
In SQL there is the LIKE command to filter results for string to match a pattern.
match_expression [ NOT ] LIKE pattern [ ESCAPE escape_character ]
The NOT is optional here, as well as the ESCAPE escape_character.
The pattern can contain following arguments:
| Wildcard | Description | Example |
|---|---|---|
% |
Any string of zero or more characters. | WHERE title LIKE ‘%programming%’ finds all book titles with the word ‘programming’ anywhere in the book title. |
_ (underscore) |
Any single character. | WHERE name LIKE ‘_ean’ finds all four-letter first names that end with ean (Dean, Sean, and so on). |
[] |
Any single character within the specified range ([a-f]) or set ([abcdef]). | WHERE name LIKE ‘[D-S]ean’ finds all first names that start with one of these letters in range (Dean, Sean, and so on). |
[^] |
Any single character not within the specified range ([^a-f]) or set ([^abcdef]). | WHERE name LIKE ‘[C,L,^K]arsen’ finds all first names that start with one of these letters in range, but not with K (Carsen, Larsen, but not Karsen). |
use the custom escape_character
If your result string already contain the [..] as content you have to escape them. You maybe have some log statements in a DB and your logger writes strings like "[SomeCategory][SomeId]": Logger is starting.. If you want to filter these results you have to escape the brackets with a SQL like the following:
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SELECT *
FROM MyDB_Table
WHERE [Message] LIKE '"\[SomeCategory\]%' ESCAPE '\'
Now you escape the brackets with the \ character like you would escape in C# strings.