QY_Book.Close;
QY_Book.SQL.Clear;
Qy_book.SQL.Add('select * from book where'''+combobox1.Text+'''='''+Edt_Matter.Text+'''');
Qy_book.Open;这个执行时没有错可是查不到
QY_Book.SQL.Clear;
Qy_book.SQL.Add('select * from book where'''+combobox1.Text+'''='''+Edt_Matter.Text+'''');
Qy_book.Open;这个执行时没有错可是查不到
QY_Book.Close;
QY_Book.SQL.Clear;
Qy_book.SQL.Add('select * from book where'+trim(combobox1.Text)+'='''+ trim(Edt_Matter.Text)+'''');
Qy_book.Open;
Qy_book.SQL.Add('select * from book where '+combobox1.Text+'='+#39+Edt_Matter.Text+#39);
试试