Text fields need special treatment in SQL. Here’s how to add two text fields:

CREATE TABLE Foo (a int, b text)--Table Foo has b as text data type.INSERT INTO Foo VALUES (1,'qwe')INSERT INTO Foo VALUES (1,'zxc')INSERT INTO Foo VALUES (2,'123')INSERT INTO Foo VALUES (2,'abc')select coalesce(convert(varchar(8000),t1.b), '')+ coalesce(convert(varchar(8000),t2.b), '')from foo t1 join foo t2on t1.a=t2.aand coalesce(convert(varchar(8000),t1.b), '')< coalesce(convert(varchar(8000),t2.b), '')