在一个查询中将2条选择语句组合在一起

Question

I need to combine 2 select statements together but i get an error:

Notice: Trying to get property of non-object

My code currently:

$sql = "(SELECT id, sijainti FROM sijainti
  UNION ALL
SELECT numero FROM tiedot)";

My code works perfectly otherwise if i try to do this only with one select statement. Any suggestions for making this work?

Answer 1

If you use UNION then number of fetched column must be equal, also name of columns must be same, so modify your query like,

$sql = "(SELECT id AS id, sijainti AS name FROM sijainti UNION ALL SELECT 0 as id, numero AS name FROM tiedot)";

may be it will help you,