The TRIM function in SQL is used to remove the character header or end of a string. The most common purpose is to remove the leading or trailing blank spaces. This function has different names in different databases: MySQL: TRIM (), RTRIM (), LTRIM (
String function string comparison function if the result length is greater than the maximum value of the max_allowed_packet system variable, the return value of the string value function is NULL. See section 7.5.2 "Adjust server Parameters ".
String
Generally, the entire string is used as the operation object, for example: search for a substring in a substring, obtain a substring, insert a substring at a certain position in the substring, and delete a substring.
Generally, the entire string is
String functionsstring comparison functionsIf the length of the result is greater than the maximum value of the Max_allowed_packet system variable, the return value of the string value function is null. See section 7.5.2, "Tuning server parameters."
Generally, the entire string is used as the operation object, for example: search for a substring in a substring, obtain a substring, insert a substring at a certain position in the substring, and delete a substring. The required and sufficient
() function to get the length of a string:Select Length (' ABCDEFG '), Length (' 0123456789 ');/*+-------------------+----------------------+| Length (' ABCDEFG ') | Length (' 0123456789 ') |+-------------------+----------------------+|
MySQL stored procedure SP explanation
1. Introduction to stored procedures
The commonly used Operating Database Language SQL statements must be compiled and then executed before execution. the Stored Procedure (Stored Procedure) is a set of SQL
A string or string (string) is a finite sequence consisting of 0 or more characters. Generally recorded as s= ' a1a2 an ' (n>=0). It is the data type that represents text in the programming language.
A string is usually used as an action object,
For operations on string positions, the first position is marked as 1.
ASCII (str)
Returns the ASCII code value of the leftmost character of the string str. If Str is an empty string, returns 0. If STR is NULL, returns NULL.
Mysql> Select ASCII (' 2
MySQL functions and Usage examples
String functions
ASCII (str)Returns the ASCII value of the first character of the string 'str' (0 is returned when 'str' is an empty string)Mysql> select ASCII ('2 ');-> 50Mysql> select ASCII (2 );-> 50Mysql>
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.