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Using GROUP_CONCAT() on bit fields returns garbage in MySQL? How to fix?
To fix, use group_concat() with addition of 0 with column. Let us first create a table −
mysql> create table DemoTable1856 ( Id int, Value bit(1) ); Query OK, 0 rows affected (0.00 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable1856 values(101,1); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1856 values(102,0); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1856 values(101,0); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1856 values(102,1); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1856 values(101,0); Query OK, 1 row affected (0.00 sec)
Display all records from the table using select statement −
mysql> select * from DemoTable1856;
This will produce the following output −
+------+-------+ | Id | Value | +------+-------+ | 101 | | | 102 | | | 101 | | | 102 | | | 101 | | +------+-------+ 5 rows in set (0.00 sec)
Here is the query to use group_concat() on bit fields and avoid returning garbage value −
mysql> select group_concat(Value+0) from DemoTable1856 group by Id;
This will produce the following output −
+-----------------------+ | group_concat(Value+0) | +-----------------------+ | 1,0,0 | | 0,1 | +-----------------------+ 2 rows in set (0.00 sec)
Updated on: 26-Dec-2019
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