mysqlsqldelimitercsv

SQL split values to multiple rows


I have table :

id | name    
1  | a,b,c    
2  | b

i want output like this :

id | name    
1  | a    
1  | b    
1  | c    
2  | b

Solution

  • If you can create a numbers table, that contains numbers from 1 to the maximum fields to split, you could use a solution like this:

    select
      tablename.id,
      SUBSTRING_INDEX(SUBSTRING_INDEX(tablename.name, ',', numbers.n), ',', -1) name
    from
      numbers inner join tablename
      on CHAR_LENGTH(tablename.name)
         -CHAR_LENGTH(REPLACE(tablename.name, ',', ''))>=numbers.n-1
    order by
      id, n
    

    Please see fiddle here.

    If you cannot create a table, then a solution can be this:

    select
      tablename.id,
      SUBSTRING_INDEX(SUBSTRING_INDEX(tablename.name, ',', numbers.n), ',', -1) name
    from
      (select 1 n union all
       select 2 union all select 3 union all
       select 4 union all select 5) numbers INNER JOIN tablename
      on CHAR_LENGTH(tablename.name)
         -CHAR_LENGTH(REPLACE(tablename.name, ',', ''))>=numbers.n-1
    order by
      id, n
    

    an example fiddle is here.