mysql查询时,表名部分为变量的查询方法

#mysql查询(表名部分为变量)：如 sys_sms_send_his_201907, 其中201907会每月变化;
#注意事项:1.where 前密码留一个空格 2. 条件中的常量不能用单引号,必要用双引号;
set @char_table = concat('sys_sms_send_his_',DATE_FORMAT( CURDATE( ) ,'%Y%m' ));
set @exec_sql = concat('select sms_id,sms_content,bill_id,send_date from ' , @char_table , ' where SMS_CONTENT like "%验证码%" and DATE_FORMAT(send_date,"%Y%m%d") = DATE_FORMAT( CURDATE( ) ,"%Y%m%d" ) ' ); 
prepare _select from @exec_sql; 
execute _select;
deallocate prepare _select;