Question

I need to build a table from several tables in MySql and I want it has two columns like:

-------------------
name | table_name |
-------------------

I’m doing this:

Create table teams as 
(
Select name from table1
union
Select name from table2
union
Select name from table3);

How could I include each table name as a second column??

Thank you!

Answer 1

Include a quoted string literal. Be sure to also give it a column alias, which will be used as the column name in the resultant table.

CREATE TABLE teams AS 
  /* Quoted string literal with column alias */
  (SELECT name, 'table1' AS `tablename` FROM table1)
  UNION 
  (SELECT name, 'table2' AS `tablename` FROM table2)
  UNION
  (SELECT name, 'table3' AS `tablename` FROM table3);

Note that since you are in effect adding a second value to each row which differentiates it from potentially similar rows in the other tables, the UNION is now the eqivalent of a UNION ALL, and duplicate rows won’t be de-duped as the plan UNION would have. Just beware, that the results may differ from what your original UNION produced.