mysql repeat function

Difference between concat and concat_ws () and group_concat (), repeat () string functions 1, concat () functions 1.1 The concat function of MySQL can connect one or more strings, such Mysql> select concat ('10 '); + -------------- + | Concat ('10')

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

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."

Yi, CONCAT (str1,str2,...)Returns the string that results from the connection parameter. If any one of the arguments is NULL, the return value is null.Mysql> Select Concat (' One ', ' one ', ' $ '); +------------------------+| Concat (' One ', ' a ',

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

From_unixtime () is the time function in MySQLDate is the parameter that needs to be processed (the parameter is a UNIX timestamp), can be a field name, or it can be a Unix timestamp stringThe following '%y%m%d ' is primarily the formatting of the

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

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 is usually used as an action object, such as finding a substring in a string, seeking a substring, inserting a substring at a point in a string, and deleting a substring. The necessary and sufficient condition for two strings to be equal is

functions for date, time \ Timestamp in SQL statements in MySQL databaseOne MySQL gets the current date time function1.1 Get the current date + time (date + times) function: Now ()Mysql> Select Now ();+―――――――+| Now () |+―――――――+| 2008-08-08 22:20:46