Try using the following:
SELECT ("test" || " " || "test2") AS expr1 ;
Update
If these are columns you can do something similar: SELECT (column1 || ” ” || column2) AS expr1 FROM your_table;
Try using the following:
SELECT ("test" || " " || "test2") AS expr1 ;
Update
If these are columns you can do something similar: SELECT (column1 || ” ” || column2) AS expr1 FROM your_table;