MySQL nurturance-mysql Foundation Enhancement (MYQL function)

MySQL Foundation Enhancement (myql function)here are only some of the most commonly used, relatively novel:String Functions:

CONCAT://String Join function
SELECT CONCAT(‘My‘, ‘S‘, ‘QL‘);        SELECT CONCAT(‘My‘, NULL, ‘QL‘);//与null连接会变null        SELECT CONCAT(14.3);        ' 14.3 '

   concat_ws  ://delimited string connection 
 mysql>  SELECT        Concat_ws (', ', ' First name ', ' Second name ', ' last Name ');         ' First name,second name,last name ' mysql>  SELECT concat_ws (', ', ' First name ', NULL, ' last Name ');  ' First name,last name ' 
 
  LOWER  (str)/ UPPER  (str)//convert string to lowercase or uppercase 
  Left  (str,x)/ Right  (str,x)//returns the leftmost X character of the string and the rightmost x character 
  SUBSTRING  (str,x,y)//       Extracts the x position of the given string by the Y-character 
 mysql> select substring (' I love MySQL ', 8,4); 
 ' MySQL ' 

Find_in_set (str,strlist)//implementation if the string str is in table strlist consisting of n substrings, returns a value of 1 to N. Strlist are composed of ', ' delimited strings.
Example 1:
CREATE TABLE Books (


Comment ' User ID ',
BookName varchar () NOT NULL,
Sort varchar (100)
);
Insert into books (Bookid,bookname,sort) values
(1, ' College English ', ' English,teach '),
(2, ' C language ', ' language,c,old '),
(3, ' Advanced mathematics ', ' teach,olding ');
Select Bookid,bookname from books where Find_in_set (' Teach ', sort);//Where sort is the column of the Book table

SELECT LENGTH(‘text‘);//返回str的长度        4

Related website:

Mysql5.7 function Address: http://dev.mysql.com/doc/refman/5.7/en/func-op-summary-ref.html
mysql5.x Manual http://doc.mysql.cn/
MySQL official website http://dev.mysql.com/
Mysql5.7 Reference Manual http://dev.mysql.com/doc/refman/5.7/en/
Other reference Manuals
Csdn-mysql Knowledge Base

Author:liuning

MySQL nurturance-mysql Foundation Enhancement (MYQL function)