Home  >  Q&A  >  body text

mysql - String replacement based on dictionary

Source table:

Dictionary table:

It is expected that the values ​​​​in the source table will be replaced according to the dictionary table. The target result is as follows:

I tried to use the replace function, but it can only replace a single one.
(Note: Since other values ​​are separated by commas, the dictionary table id can be 1~100, so it needs to be replaced with a regular expression, otherwise 12 will be split by id1 and 2. open)

PHPzPHPz2735 days ago986

reply all(1)I'll reply

  • 给我你的怀抱

    给我你的怀抱2017-05-18 10:52:38

    Recursive function written by myself

    DELIMITER $$
    DROP FUNCTION IF EXISTS junk.StringReplaceSplit $$
    CREATE FUNCTION junk.StringReplaceSplit (v_str VARCHAR(1024), v_split VARCHAR(1024)) RETURNS VARCHAR(1024)
    DETERMINISTIC
    BEGIN
      DECLARE rv VARCHAR(1024);
      DECLARE splist_count INT;
      DECLARE i INT;
      DROP TEMPORARY TABLE IF EXISTS tmp_table;
      CREATE TEMPORARY TABLE tmp_table(v_key VARCHAR(100));
     
      SET i = 1;
      set splist_count = (length(v_str)-length(replace(v_str, v_split,'')))/length(v_split)+1;
      WHILE i <= splist_count DO
        INSERT INTO tmp_table
          SELECT REPLACE(substring(substring_index(v_str, v_split, i),
                         length(substring_index(v_str, v_split, i-1)) + 1),
                          v_split, '');
        SET i = i + 1;
      END WHILE;
      SELECT replace(group_concat(ifnull(wordlist.word, tmp_table.v_key)), ',', v_split) INTO rv
        from tmp_table
        LEFT JOIN wordlist on wordlist.id=tmp_table.v_key;
      RETURN rv;
    END $$
    DELIMITER ;

    Effect:
    Source table

    mysql> select * from teststring;
    +----+----------------------------+
    | id | String                     |
    +----+----------------------------+
    |  1 | 1,2,3,4,5                  |
    |  2 | 4,5,7,8,84                 |
    |  3 | key,23,344,12,3,9,34,3,1,3 |
    +----+----------------------------+
    3 rows in set (0.00 sec)
    

    Dictionary table

    mysql> select * from wordlist;
    +----+-------+
    | id | word  |
    +----+-------+
    | 1  | one   |
    | 2  | two   |
    | 3  | three |
    | 4  | four  |
    | 5  | five  |
    | 7  | six   |
    | 8  | eight |
    | 9  | nine  |
    | 10 | ten   |
    +----+-------+
    9 rows in set (0.00 sec)

    Example:

    mysql> SELECT id, StringReplaceSplit(String,',') transform from teststring ;
    +----+---------------------------------------------+
    | id | transform                                   |
    +----+---------------------------------------------+
    |  1 | one,two,three,four,five                     |
    |  2 | four,five,six,eight,84                      |
    |  3 | key,23,344,12,three,nine,34,three,one,three |
    +----+---------------------------------------------+
    3 rows in set (0.04 sec)

    The function needs to be optimized.

    reply
    0
  • Cancelreply