mysql escape character

Mysql is a commonly used relational database management system. It has powerful data processing capabilities and flexible data storage methods, and is widely used in the development of Internet and enterprise-level applications. When using Mysql, we often need to use escape characters to deal with some special characters. This article will introduce how to use escape characters in Mysql.

1. What is an escape character

The escape character is a special character used to tell the computer how to process some special characters or strings. In Mysql, escape characters are used to process some special characters, such as single quotes, double quotes, backslashes, etc. Commonly used escape characters in Mysql include:,',",
,,, etc.

2. Use of escape characters

2.1 Single quotes and double quotes

In Mysql, single quotes and double quotes are used to represent strings. When you need to use single quotes or double quotes in a string, you need to use an escape character to escape. For example:

INSERT INTO t_user (username, password) VALUES (''test'', '"123456"');

The above SQL statement inserts a record, the user name is 'test', the password is "123456", single quotes and double quotes are used in the string, and they need to be escaped using escape characters.

2.2 Backslash

Backslash is also an escape character in Mysql, used to represent special characters or backslashes in strings. For example:

SELECT * FROM t_user WHERE username LIKE '%_%' ESCAPE '';

Above The SQL statement queries users whose user names contain underscore _, because the underscore is also a special character and needs to be processed using an escape character. In addition, the statement uses the ESCAPE clause after the LIKE operator, specifying the escape character as , this can avoid conflicts.

2.3 Line feed, carriage return and tab characters

In Mysql, line feed character
, carriage return character and tab character are also a kind of conversion. Symbols are used to represent special characters. For example:

INSERT INTO t_user (username, password, description) VALUES ('test', '123456', 'Hello
World!    Welcome to Mysql!');

The above SQL statement inserts a record with the user name test, password 123456, and description as "Hello
World! Welcome to Mysql!" , where
represents a newline character and represents a tab character.

3. Summary

The escape character is a very important special character in Mysql. It can Help us deal with special characters and strings to avoid some unexpected errors. When using escape characters, we need to pay attention to the syntax and usage of escape characters to ensure the correctness of the statement. At the same time, when processing some special characters, we also need to pay attention to the syntax and usage of escape characters. You can use some built-in functions provided in Mysql, such as REPLACE() and CONCAT(), etc., to simplify programming difficulty and improve code readability.

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