How Can I Use Special Characters Effectively in SQL LIKE Clauses?

Special Characters for SQL LIKE Clause

The SQL LIKE operator allows for precise string matching in queries. To enhance matching capabilities, various special characters can be used in the LIKE clause. Here's a compilation of these special characters for SQL Server and other popular database management systems.

SQL Server

1. %: Represents any string of any length, including the empty string.
2. _: Matches any single character.
3. [specifier]: Matches any character within the specified character range. For example, [a-z] matches any lowercase letter.
4. ¹: Matches any character outside the specified character range.
5. ESCAPE clause: Denotes an escape character used to escape special characters in the LIKE pattern. For instance, 0!%%' ESCAPE '!' will match '30%' because the '!' before the % escapes it.
6. ' characters: Must be escaped with ' when used as part of the LIKE pattern. For example, they're becomes they''re.

MySQL

1. %: Any string of zero or more characters.
2. _: Any single character.
3. ESCAPE clause: Enables the use of an escape character, similar to SQL Server.

Oracle

1. %: Any string of zero or more characters.
2. _: Any single character.
3. ESCAPE clause: Provides the ability to escape special characters in the pattern.

Sybase

1. %: Any string of any length.
2. _: Matches a single character.
3. [specifier]: Matches characters within the range specified.
4. ¹: Matches characters outside the range specified.

Progress

1. %: Any string of zero or more characters.
2. _: Any single character.

PostgreSQL

1. %: Any string of zero or more characters.
2. _: Any single character.
3. ESCAPE clause: Facilitates the use of an escape character in the pattern.

ANSI SQL92

1. %: Any string of zero or more characters.
2. _: Any single character.
3. ESCAPE clause: Only included when explicitly specified.

PostgreSQL - SIMILAR TO Operator

In addition to the special characters available in the LIKE operator, PostgreSQL offers the SIMILAR TO operator, which extends the matching capabilities with the following additional characters:

1. [specifier]: Matches characters within a range.
2. ¹: Matches characters outside a range.
3. |: Represents the logical OR operator.
4. *: Indicates repetition of the previous element zero or more times.
5. : Indicates repetition of the previous element one or more times.
6. (): Groups elements together.

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1. specifier ↩

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