query的问题

Question

我用SQL.Add()语句动态对query添加了数据，现在我要读出来，用
str:string;    
with query do
 str:=FieldByName('ID').AsString;
调试时出错提示：varient references to automative ......
 该怎么解决啊

Answer 1

Query1.Sql.Clear;
Query1.Sql.Add(...);
Query1.Open;
Query1.First;
str:=Query1.FieldByName('ID').AsString;

Answer 2

SQL.Clear;
                          SQL.Add('SELECT ID');
                          SQL.Add ('FROM COURSE_FREE1');
                          SQL.Add('WHERE TERM='''+course_ComboBox10.Text+'''');
                          SQL.Add ('AND SPECIALIZE_CODE='''+special+'''');
                          SQL.Add('AND STATE='''+coursepro+'''');
                          SQL.Add ('AND COMP='''+'0'+'''');
                          SQL.Add('AND CLASS='''+course_ComboBox14.Text+'''' );
                          ExecSQL;

Answer 3

close;
SQL.Clear;
                          SQL.Add('SELECT ID');
                          SQL.Add ('FROM COURSE_FREE1');
                          SQL.Add('WHERE TERM='''+course_ComboBox10.Text+'''');
                          SQL.Add ('AND SPECIALIZE_CODE='''+special+'''');
                          SQL.Add('AND STATE='''+coursepro+'''');
                          SQL.Add ('AND COMP='''+'0'+'''');
                          SQL.Add('AND CLASS='''+course_ComboBox14.Text+'''' );
                          open;
                  应该可以

Answer 4

楼主，在添加完数据后，需要将query结果集打开
及执行query1.open;
然后再执行你的那段代码，就行了

Answer 5

var  
  str:string;
  i:integer;
begin
adoquery1.sql.clear;
adoquery1.close;
adoquery1.sql.add('select * from COURSE_FREE1');
adoquery1.open;if not adoquery1.isempty then //如果查询的数据不为空
begin
     for i:=1 to adoquery1.recordcount do
     with adoquery1 do
     begin
        str:=adoquery1.FieldValues['id'];
        adoquery1.next;
     end;
end;

Answer 6

：）
不会是没有open吧，呵呵

Answer 7

老兄要用open 返回结果集，不能用execsql，只执行返回执行结束的状态