Find duplicate records and give result in concat string

group-concat, mysql, sql

Solution

Join the two tables and use `GROUP_CONCAT`

SELECT  a.NumA, GROUP_CONCAT(DISTINCT b.codeB)
FROM    table1 A
        INNER JOIN table2 b
          on a.numA = b.numB
GROUP BY a.NumA

SQLFiddle Demo

Problem

I have 2 tables where some of the records will be identical (except for the id) Table A: ``` id, numA, codeA 6, 34, aa 7, 34, bb 8, 567, bc ``` Table B ``` id, numB, codeB 1, 34, aa 2, 34, bb 3, 567, bc ``` I need to run a query on Table B which will check if given combination of num and code exists in Table A and will give the result in such format: ``` num, concat code 34, (aa,bb) 567, (bc) ```

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