我的这句更新写的对吗？为什么提示类型不兼容啊？

Question

SQL.Add('update cost set student_id='''+Trim(DBEdit1.text)+''',shoule_cost='''+Trim(DBEdit2.text)+''',fact_cost='''+Trim(DBEdit3.text)+''',cost_date='''+DateTimePicker1.date+''',people='''+Trim(DBEdit4.text)+''',description='''+Trim(DBMemo1.text)+'''');
      ParambyName('student_id').AsString:=Trim(DBEdit1.Text);
      ParambyName('should_cost').AsString:=Trim(DBEdit2.Text);
      ParambyName('fact_const').AsString:=Trim(DBEdit3.Text);
      ParambyName('cost_date').AsDateTime:=DateTimePicker1.date;
      ParambyName('people').AsString:=Trim(DBEdit4.Text);
      ParambyName('description').AsString:=Trim(DBMemo1.text);

Answer 1

sqltxt:='asdfasdf'+
        'sdfasdfasdf'+
        'asdf';

Answer 2

cost_date='''+DateTimePicker1.date+'''cost_date='''+datetostr(DateTimePicker1.date)+'''

Answer 3

SQL语句里没有加参数下面写一大堆ParamByName...干嘛？

Answer 4

或者改成
SQL.Add('update cost set student_id=:student_id, shoule_cost=:shoule_cost, fact_cost=:fact_cost, cost_date=:cost_date, people=:people, description=:description');
再加下面的ParamByName...