SQLite ESCAPE

One of the useful features of SQLite is the ESCAPE operator, which is used in conjunction with the LIKE operator to search for specific characters in a string.

The LIKE operator is used to match a pattern with a string. It is commonly used to search for strings that match a particular pattern or contain a certain substring. The syntax of the LIKE operator is as follows:

SELECT column_name(s)
FROM table_name
WHERE column_name LIKE pattern;

In this syntax, the column_name refers to the column in the table that contains the string data, the table_name is the name of the table, and the pattern is the string pattern to search for. The pattern can include special characters that have special meanings in the context of the LIKE operator. For example, the % character is used to match any sequence of zero or more characters.

The ESCAPE operator is used to specify a character that should be used as the escape character for the LIKE operator. This means that any special characters that would normally be interpreted by the LIKE operator as having special meanings can be escaped using the escape character. This allows users to search for strings that contain special characters without having those characters interpreted as special characters by the LIKE operator.

Syntax

The syntax for using the ESCAPE operator is as follows:

SELECT column_name(s)
FROM table_name
WHERE column_name LIKE pattern ESCAPE escape_character;

In this syntax, the escape_character is the character that should be used as the escape character. Any special characters that appear in the pattern string can be escaped using this character.

Example

For example, if you wanted to search for strings that contain the @ character, you could use the following query:

SELECT *
FROM users
WHERE email LIKE '%@%%' ESCAPE '%';

In this query, the % character is used as the wildcard character to match any sequence of characters before or after the @ character. The %% sequence is used to escape the % character, so that it is not interpreted as a wildcard character by the LIKE operator. The % character is specified as the escape character using the ESCAPE operator.

In summary, the ESCAPE operator in SQLite is a useful feature that allows users to search for strings that contain special characters without having those characters interpreted as special characters by the LIKE operator.