you know there is an insert statement which is used to add data to a table. but did you know that there is an insert function which will replace certain characters within a string?
INSERT ( ) function in MySQL is used to insert a substring at the specified position up to the specified number of characters.
Let us consider this example.
set @str:='This is nothing';
The variable @str has a string value “This is nothing”. Suppose you want to change “nothing” into “everything” in this string. You can use INSERT ( ) function as shown below
select INSERT(@str,9,2,'every');
The INSERT ( ) function replaces the characters starting from the position 9 to next 2 characters by “everything”. So in the string part “nothing”, no is replaced by “every” and the full string becomes “This is everything” .

You can also add a string between two strings as shown below
set @str:='This is nothing'; select INSERT(@str,9,0,'not ');
The result is “This is not nothing”. When the third parameter is 0, it will not replace any characters, but append it at the starting position defined in the second parameter
Note: This INSERT ( ) function is functionally equivalent to SQL Server’s STUFF ( ) function. You can refer the usage of STUFF ( ) function in this post .
Reference: Pinal Dave ( http://blog.sqlauthority.com )
每个人都需要一台速度更快、更稳定的 PC。随着时间的推移,垃圾文件、旧注册表数据和不必要的后台进程会占用资源并降低性能。幸运的是,许多工具可以让 Windows 保持平稳运行。
Copyright 2014-2025 https://www.php.cn/ All Rights Reserved | php.cn | 湘ICP备2023035733号