mysql 分页存储过程

mysql中的分页通用存储过程，7个参数

p_table_name    表名

p_filelds    取的字段，可以用*

p_page_size    每页的记录数

p_page_now    当前页

p_order_string    排序的字段

p_where_string    检索条件

p_out_rows    符合条件的总记录数

DROP PROCEDURE IF EXISTS pr_pager;
CREATE PROCEDURE pr_pager(

IN    p_table_name        VARCHAR(1024),
IN    p_fields            VARCHAR(1024),
IN    p_page_size            INT,
IN    p_page_now            INT,
IN    p_order_string        VARCHAR(128),
IN    p_where_string        VARCHAR(1024),
OUT    p_out_rows            INT

)
NOT DETERMINISTIC
SQL SECURITY DEFINER
COMMENT '分页存储过程'

BEGIN

/*定义变量*/
DECLARE m_begin_row INT DEFAULT 0;
DECLARE m_limit_string CHAR(64);

/*构造语句*/
SET m_begin_row = (p_page_now - 1) * p_page_size;
SET m_limit_string = CONCAT(' LIMIT ', m_begin_row, ', ', p_page_size);

SET @COUNT_STRING = CONCAT('SELECT COUNT(*) INTO @ROWS_TOTAL FROM ', p_table_name, ' ', p_where_string);
SET @MAIN_STRING = CONCAT('SELECT ', p_fields, ' FROM ', p_table_name, ' ', p_where_string, ' ', p_order_string, m_limit_string);

/*预处理*/
PREPARE count_stmt FROM @COUNT_STRING;
EXECUTE count_stmt;
DEALLOCATE PREPARE count_stmt;
SET p_out_rows = @ROWS_TOTAL;

PREPARE main_stmt FROM @MAIN_STRING;
EXECUTE main_stmt;
DEALLOCATE PREPARE main_stmt;

END