Description of basic functions in MySQL stored procedure (1)

The following articles mainly introduce the basic functions in the MySQL stored procedure, that is, the introduction of the mathematical functions in the string and MySQL stored procedure. The following describes the specific content, I hope you will be helpful in your future studies.

I. 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 processing strings in MySQL stored procedures, 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) // remove the specified character FROM the specified position

UCASE (string2) // converts to uppercase

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

SPACE (count) // generate count Spaces