query.sql.clear; query.sql.text := 'select * from table1 where a=''a'''; query.open; if query.recordcount > 0 then begin query.edit; query.fieldbyname('a').asstring := 'b'; query.post; end; query.close;
//或者直接用SQL更新 query.sql.clear; query.sql.text := 'update table1 set a=''a'''; query.execsql;
query.sql.text := 'select * from table1 where a=''a''';
query.open;
if query.recordcount > 0 then
begin
query.edit;
query.fieldbyname('a').asstring := 'b';
query.post;
end;
query.close;
query.sql.clear;
query.sql.text := 'update table1 set a=''a''';
query.execsql;