Can Regular Expressions Parse Comma-Separated Strings into MySQL Temporary Tables?

Utilizing RegEx to Parse Comma-Separated Strings into MySQL Temp Tables

Question:

Is it possible to parse a comma-separated string into a temporary MySQL table using regular expressions?

Answer:

While MySQL lacks a built-in function for string splitting, various workarounds exist. One approach involves custom functions and looping mechanisms to break down the string into its components.

Custom Function for String Splitting:

CREATE FUNCTION SPLIT_STR(
  x VARCHAR(255),
  delim VARCHAR(12),
  pos INT
)
RETURNS VARCHAR(255)
RETURN REPLACE(SUBSTRING(SUBSTRING_INDEX(x, delim, pos),
       LENGTH(SUBSTRING_INDEX(x, delim, pos -1)) + 1),
       delim, '');

Looping and Incrementing the Custom Function:

DELIMITER $$  

CREATE PROCEDURE ABC(fullstr)

   BEGIN
      DECLARE a INT Default 0 ;
      DECLARE str VARCHAR(255);
      simple_loop: LOOP
         SET a=a+1;
         SET str=SPLIT_STR(fullstr,"|",a);
         IF str='' THEN
            LEAVE simple_loop;
         END IF;
         #Do Inserts into temp table here with str going into the row
         insert into my_temp_table values (str);
   END LOOP simple_loop;
END $$

This approach allows you to parse the split string and dynamically insert the components into a temporary table using MySQL's looping capabilities.

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