Question

DELIMITER $$

DROP PROCEDURE IF EXISTS logger $$
CREATE PROCEDURE logger(IN errorz VARCHAR(50),IN table_name VARCHAR(50))
BEGIN

DECLARE t_name VARCHAR(50);
DECLARE link_id_var INT;
DECLARE error_type_var VARCHAR(30);
DECLARE source_url_var VARCHAR(500);
DECLARE done INT DEFAULT 0;

DECLARE curl  CURSOR FOR  SELECT link_id, anchor_match, anchor_match FROM cursor_temp;

DECLARE CONTINUE HANDLER FOR NOT FOUND SET done=1;


DROP TEMPORARY TABLE IF EXISTS cursor_temp;
SET @query1 = CONCAT('
    CREATE TEMPORARY TABLE cursor_temp AS
        SELECT p.link_id, anchor_match, source_url 
        FROM ',table_name,' AS p
             INNER JOIN link_results AS l
                 ON p.page_r_id = l.page_r_id
             INNER JOIN links AS ls
                 ON ls.link_id = p.link_id
        WHERE anchor_match="None"
    ');
PREPARE stmt FROM @query1; EXECUTE stmt; DEALLOCATE PREPARE stmt;


OPEN curl;

my_loop:LOOP

FETCH curl INTO link_id_var,error_type_var,source_url_var;

INSERT INTO errors (link_id,error_type,source_url) VALUES (link_id_var,errorz,source_url_var) ON DUPLICATE KEY UPDATE error_type=errorz,source_url=source_url_var;

IF done=1 THEN
LEAVE my_loop;
END IF;
END LOOP my_loop;
CLOSE curl;

DROP TEMPORARY TABLE IF EXISTS cursor_temp;

END $$

当我执行声明时：

call logger('anchor','page_results');

我将其他表中的源url字段设为'None'。为什么呢？

Answer 1

这是因为所有DECLARE语句都必须位于存储过程的顶部。

您需要在所有SET @t_name=table_name;语句后移动此DECLARE语句。

请参阅Manual。

编辑：您无法访问游标中的变量表名称。或者，您可以使用动态sql并将结果存储在临时表中，并在游标选择中使用该表。

CREATE PROCEDURE logger(IN errorz VARCHAR(50),IN table_name VARCHAR(50))
BEGIN

    DECLARE t_name VARCHAR(50);
    DECLARE link_id_var INT;
    DECLARE error_type_var VARCHAR(30);
    DECLARE source_url_var VARCHAR(500);
    DECLARE done INT DEFAULT 0;

    DECLARE curl  CURSOR FOR  SELECT link_id, anchor_match, anchor_match FROM cursor_temp;

    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done=1;


    DROP TEMPORARY TABLE IF EXISTS cursor_temp;
    SET @query1 = CONCAT('
        CREATE TEMPORARY TABLE cursor_temp AS
            SELECT p.link_id, anchor_match, anchor_match
            FROM ',table_name,' AS p
                 INNER JOIN link_results AS l
                     ON p.page_r_id = l.page_r_id
                 INNER JOIN links AS ls
                     ON ls.link_id = p.link_id
            WHERE anchor_match="None"
        ');
    PREPARE stmt FROM @query1; EXECUTE stmt; DEALLOCATE PREPARE stmt;


    OPEN curl;

    my_loop:LOOP

    FETCH curl INTO link_id_var,error_type_var,source_url_var;

    INSERT INTO errors (link_id_var,error_type,source_url) VALUES (link_id_var,errorz,source_url_var) ON DUPLICATE KEY UPDATE error_type=error,source_url=source_url_var;

    IF done=1 THEN
    LEAVE my_loop;
    END IF;
    END LOOP my_loop;
    CLOSE curl;

    DROP TEMPORARY TABLE IF EXISTS cursor_temp;
END$$

在mysql中声明变量

1 个答案: