为什么我收到此错误？
@H_404_6@CREATE DEFINER=`root`@`localhost` PROCEDURE `selectrecords`(tablename varchar(50)) begin set @table_name=tablename; set @sql_text=concat('Select * from @table_name'); prepare statement from @sql_text; execute statement; deallocate prepare statement; end
错误：
@H_404_6@....to use near '@table_name' at line 1
我的代码是正确的,但我不明白为什么….
最佳答案
我想你的意思是,
@H_404_6@CREATE PROCEDURE `selectrecords`(tablename varchar(50)) begin set @sql_text = concat('Select * from ',tablename); prepare statement from @sql_text; execute statement; deallocate prepare statement; end
即使在动态sql中,也不能参数化表名和列名,因此您唯一的选择是与字符串连接.只有值可以放在占位符中.
更新1
@H_404_6@CREATE PROCEDURE `selectrecords`(tablename varchar(50)) begin set @val = idnumber; set @sql_text = concat('Select * from ',tablename,' WHERE id = ?'); prepare statement from @sql_text; execute statement USING @val; deallocate prepare statement; end