Query的查询

Question

query1.close;
query1.sql.clear;
query1.sql.add('select * from table where year(rq)>=:da');
--------------------------------------------------------------------
query1.parambyname('da').asdatetime:=dateedit1.date;//控件时间
query1.open;

Answer 1

query1.close;
query1.sql.clear;
query1.sql.add('select * from table where year(rq)>=year(:mdate)');
--------------------------------------------------------------------
query1.parambyname('mdate').asdatetime:=dateedit1.date;//控件时间
query1.open;

Answer 2

should be:query1.sql.add('select * from table where year(rq)>=year(:mdate)');

Answer 3

query1.close;
query1.sql.clear;
query1.sql.add('select * from table where year(rq)>=year(:mdate)');
query1.Params.Clear;//加上这句
query1.Params.ParseSQL(query1.Text,True);//加上这句
query1.parambyname('mdate').asdatetime:=dateedit1.date;//控件时间
query1.open;

Answer 4

query1.close;
query1.sql.clear;
query1.sql.add('select * from table where year(rq)>=:mdate');
--------------------------------------------------------------------
query1.parambyname('mdate').asinteger:=yearof(dateedit1.date);//控件时间
query1.open