MySQL Select Query to generate dynamic column Result

Question

I need to write a query that returns a Column Dynamically. For example I have a table tblTest with columns:

Id, Name,   Type,  Amount
1, Receipt, Cash   100
         


        

Answer 1

Hej,

Hope i got you right.

select name, type, sum(CASE WHEN Type in (select DISTINCT sub.type from 
tblTest sub) THEN Amount ELSE 0 END) as "sum" from tblTest
group by name, type;

Answer 2

You need to use Dynamic pivot

Create your pivot query Dynamically.

The main steps are as follows

1. Declare a variable @sql to carry your SUM function and CASW WHEN Expression
2. use CONCAT to combine your SUM function and CASW WHEN Expression string and main select string.
3. use EXECUTE function execute SQL Dynamically.

look like this.

SET @sql = NULL;
SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      'SUM(CASE WHEN Type =''',
      Type,
      ''' THEN Amount END) AS ',
      Type
    )
  ) INTO @sql
FROM tblTest;

SET @sql = CONCAT('SELECT
                    Name,', @sql, ' 
                   FROM tblTest
                   GROUP BY
                    Name;');

PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

Result

    Name    Cash    Card    Cheque
1   Payment 300     NULL    400
2   Receipt 200      350    250

SQLfiddle