Question

I have a task to make a summary table of a few thousand other tables containing thousands of records. The summary table should contain:

1. non redundant list of “records”;
2. number of tables containing that “record”
3. names of tables containing that “record”

Example would be:

Table_1
nameA
nameB
nameC

Table_2
nameB
nameC
nameD

Table_3
nameC
nameD
nameE

Result should be something like this

Record_name  Number  Table_names
nameA        1       Table_1
nameB        2       Table_1, Table_2
nameC        3       Table_1, Table_2, Table_3
nameD        2       Table_2, Table_3
nameE        1       Table_3

Perhaps it is not to complicated thing to do, but, since I’m quite new to mysql, I hope to get some advice and help from you guys!

Answer 1

SELECT  col1 as `Record Number`, 
        COUNT(*) as `Number`, 
        GROUP_CONCAT(_name) as `table name`
FROM
(
    SELECT col1, 'table_1' as _name FROM table_1
    UNION ALL
    SELECT col1, 'table_2' as _name FROM table_2
    UNION ALL
    SELECT col1, 'table_3' as _name FROM table_3
) a
GROUP BY col1

• SQLFiddle Demo