How to process strings in a MySQL database

The following articles mainly describe the basic function type of the MySQL database stored procedure, that is, the string, which is often used in actual operations, the following articles mainly describe the timing application and related functions of MySQL strings.

String type

CHARSET (str) // returns the string Character Set

CONCAT (string2 [,...]) // connection string

INSTR (string, substring) // returns the position of the first occurrence of the substring in the string. If no position exists, 0 is returned.

LCASE (string2) // converts it to lowercase

LEFT (string2, length) // take the length from the LEFT of string2

LENGTH (string) // string LENGTH

LOAD_FILE (file_name) // read content from the file

LOCATE (substring, string [, start_position]) is the same as INSTR, but the start position can be specified.

LPAD (string2, length, pad) // repeat pad to start with string until the string length is length

LTRIM (string2) // remove leading Spaces

REPEAT (string2, count) // REPEAT count times

REPLACE (str, search_str, replace_str) // REPLACE search_str with replace_str in str

RPAD (string2, length, pad) // use pad after str until the length is length.

RTRIM (string2) // remove backend Spaces

STRCMP (string1, string2) // compare the size of two strings by character,

SUBSTRING (str, position [, length]) // starts from the position of str and takes length characters,

Note: When the MySQL database processes strings, the default subscript of the first character is 1, that is, the parameter position must be greater than or equal to 1.

 
 

  
  
MySQL> select substring('abcd',0,2);  
  
  
+-----------------------+  
  
  
| substring('abcd',0,2) |  
  
  
+-----------------------+  
  
  
| |  
  
  
+-----------------------+  
  
  
1 row in set (0.00 sec)  
  
  
MySQL> select substring('abcd',1,2);  
  
  
+-----------------------+  
  
  
| substring('abcd',1,2) |  
  
  
+-----------------------+  
  
  
| ab |  
  
  
+-----------------------+  
  
  
1 row in set (0.02 sec)  
  
  
TRIM([[BOTH|LEADING|TRAILING] [padding] FROM]string2)  
 
 

Removes specified characters from a specified position.

UCASE (string2) // converts to uppercase

RIGHT (string2, length) // gets the last length character of string2

SPACE (count) // generate count Spaces

The above content is an introduction to the strings in the basic functions of the MySQL database stored procedure. I hope you will have some gains.