Question

我已经编写了一个mysql过程来比较两个数据库并添加缺少的表和列，但是显示错误，我无法发现错误，该过程请帮助我清除该错误

DELIMITER $$
CREATE PROCEDURE database_comparison(IN original_db varchar(255),IN compare_db varchar(255))
BEGIN
DECLARE table_name_o varchar(255);
DECLARE column_name_o varchar(255);
DECLARE cursor_sts int default 0;
DROP TABLE IF EXISTS temp_db.original_database_list;
create temporary  table temp_db.original_database_list SELECT TABLE_NAME,COLUMN_NAME,'table not exists' as flag_t,'column not exists' as flag_c FROM information_schema.`COLUMNS` where TABLE_SCHEMA=original_db and TABLE_NAME not like 'z%' and TABLE_NAME not like '%bk%';
DROP TABLE IF EXISTS temp_db.compare_database_list;
create temporary  table temp_db.compare_database_list SELECT TABLE_NAME,COLUMN_NAME,'table not exists' as flag_t,'column not exists' as flag_c FROM information_schema.`COLUMNS` where TABLE_SCHEMA=compare_db and TABLE_NAME not like 'z%' and TABLE_NAME not like '%bk%';
update temp_db.original_database_list a join temp_db.compare_database_list b on a.TABLE_NAME=b.TABLE_NAME set a.flag_t='',b.flag_t='';
update temp_db.original_database_list a join temp_db.compare_database_list b on a.TABLE_NAME=b.TABLE_NAME and a.COLUMN_NAME=b.COLUMN_NAME set a.flag_c='',b.flag_c='';
DECLARE table_cursor CURSOR FOR select distinct TABLE_NAME from temp_db.original_database_list where flag_t<>'';
DECLARE CONTINUE HANDLER FOR NOT FOUND SET cursor_sts=1;
OPEN table_cursor;
table_loop:LOOP
    IF cursor_sts=1 THEN
        SET cursor_sts=0;
        LEAVE table_loop;
    END IF;
    FETCH table_cursor INTO table_name_o;
    create table compare_db.table_name_o like original_db.table_name_o;
END LOOP table_loop;
CLOSE  table_cursor;
SET table_name_o='';
DECLARE column_cursor CURSOR FOR select distinct TABLE_NAME,COLUMN_NAME from temp_db.original_database_list where flag_t='' and flag_c<>'';
DECLARE CONTINUE HANDLER FOR NOT FOUND SET cursor_sts=1;
OPEN column_cursor;
column_loop:LOOP
    IF cursor_sts=1 THEN
        LEAVE table_loop;
    END IF;
    FETCH column_cursor INTO table_name_o,column_name_o;
    SET @query =(SELECT concat('alter table `',compare_db,'`.`',table_name_o,'` add `',column_name_o,'` ',column_type,' not null;') FROM information_schema.`COLUMNS` where TABLE_NAME=table_name_o and a.COLUMN_NAME=column_name_o and TABLE_SCHEMA=original_db);
    PREPARE stmt FROM @query;
    EXECUTE stmt;
    DEALLOCATE PREPARE stmt;
END LOOP column_loop;
CLOSE  column_cursor;
END $$
DELIMITER ;

Answer 1

**this is the corrected procedure it works**

DELIMITER $$
    DROP PROCEDURE IF EXISTS database_comparison$$
    CREATE PROCEDURE database_comparison(IN original_db varchar(255),IN compare_db varchar(255))
    BEGIN
    DECLARE table_name_o varchar(255);
    DECLARE column_name_o varchar(255);
    DECLARE cursor_sts int default 0;
    DEClARE table_cursor CURSOR FOR  
        select distinct TABLE_NAME from temp_db.original_database_list where flag_t<>'';
    DECLARE column_cursor CURSOR FOR 
        select distinct TABLE_NAME,COLUMN_NAME from temp_db.original_database_list where flag_t='' and flag_c<>'';
    DECLARE CONTINUE HANDLER 
        FOR NOT FOUND SET cursor_sts=1;
    DROP TABLE IF EXISTS temp_db.original_database_list;
    create table temp_db.original_database_list SELECT TABLE_NAME,COLUMN_NAME,'table not exists' as flag_t,'column not exists' as flag_c FROM information_schema.`COLUMNS` where TABLE_SCHEMA=original_db and TABLE_NAME not like 'z%' and TABLE_NAME not like '%bk%';
    DROP TABLE IF EXISTS temp_db.compare_database_list;
    create table temp_db.compare_database_list SELECT TABLE_NAME,COLUMN_NAME,'table not exists' as flag_t,'column not exists' as flag_c FROM information_schema.`COLUMNS` where TABLE_SCHEMA=compare_db and TABLE_NAME not like 'z%' and TABLE_NAME not like '%bk%';
    ALTER TABLE temp_db.original_database_list ADD index(TABLE_NAME,COLUMN_NAME);
    ALTER TABLE temp_db.compare_database_list ADD index(TABLE_NAME,COLUMN_NAME);
    update temp_db.original_database_list a join temp_db.compare_database_list b on a.TABLE_NAME=b.TABLE_NAME set a.flag_t='',b.flag_t='';
    update temp_db.original_database_list a join temp_db.compare_database_list b on a.TABLE_NAME=b.TABLE_NAME and a.COLUMN_NAME=b.COLUMN_NAME set a.flag_c='',b.flag_c='';
    OPEN table_cursor;
    table_loop:LOOP
    FETCH table_cursor INTO table_name_o;
        IF cursor_sts=1 THEN
            SET cursor_sts=0;
            LEAVE table_loop;
        END IF;
        SET @query1 =concat('create table ',compare_db,'.',table_name_o,' like ',original_db,'.',table_name_o);
        PREPARE stmt1 FROM @query1;
        EXECUTE stmt1;
        DEALLOCATE PREPARE stmt1;
    END LOOP table_loop;
    CLOSE  table_cursor;
    SET table_name_o='';
    OPEN column_cursor;
    column_loop:LOOP
    FETCH column_cursor INTO table_name_o,column_name_o;
        IF cursor_sts=1 THEN
            LEAVE column_loop;
        END IF;
        SET @query =(SELECT concat('alter table `',compare_db,'`.`',table_name_o,'` add `',column_name_o,'` ',column_type,' not null;') FROM information_schema.`COLUMNS` where TABLE_NAME=table_name_o and COLUMN_NAME=column_name_o and TABLE_SCHEMA=original_db);
        PREPARE stmt FROM @query;
        EXECUTE stmt;
        DEALLOCATE PREPARE stmt;
    END LOOP column_loop;
    CLOSE  column_cursor;
    END $$
    DELIMITER ;

要比较两个mysql数据库，请使用过程

1 个答案: