MySQL_Table_Union_Query_Alias

select id from t_book;
select id from t_bookType;
select id from t_book union select id from t_bookType;

select id from t_book union all select id from t_bookType;

select * from t_book tb where tb.id>=3;
select tb.id, tb.bookName from t_book tb where tb.id>=3;
select tb.id, tb.bookName Book_Name from t_book tb where tb.id>=3;
select tb.id, tb.bookName as Book_Name from t_book tb where tb.id>=3;