Wildcards in SQL Server

Wildcards are useful when searching for items using LIKE clause. MSSQL allows a few wildcard specifier. The most commonly used is the % character. There are some other wildcards available in MSSQL. The underscore character `_` is used for a single character wildcard. the `[]` wildcard indicates that any single character set or range specified in it will be a wild card. If the first character is ^ in the `[]` set or range, it is equivalent to single character `not`matching.

Now we do have literal characters that uses the wildchard character. How do we defile the literal characters in the search? it is quite simple. Simply enclose the character between `[]`. That will include the `[` and `]` also. Another character is the single quote. Well, simply add another single quote to it. Finally there is an ESCAPE clause where you could define a escape character. Normally the escape character is a backslash. just add ESCAPE `\' to the end of the where clause.

In Oracle, it has quite similar syntax except that it does not have `[]`. It does uses ESCAPE clause exactly like MSSQL. I think we should use the ESCAPE clause as standard except under special circumstances then we use the `[]` wildcard.