MySQL循環遍歷表

我想輸出每個包含first_name列的表的數據。我將以下過程放在一起，但在我的循環中，mysql逐字地解釋表名，而不是評估變量table_name。什麼是修復？MySQL循環遍歷表

delimiter // 

drop procedure if exists hunt // 
create procedure hunt() 
begin 
    DECLARE done int default false; 
    DECLARE table_name CHAR(255); 

    DECLARE cur1 cursor for SELECT TABLE_NAME FROM INFORMATION_SCHEMA.COLUMNS 
     WHERE TABLE_SCHEMA = "wholesale_production" and COLUMN_NAME LIKE "%first%" ; 
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE; 
    open cur1; 

    myloop: loop 
     fetch cur1 into table_name; 
     if done then 
      leave myloop; 
     end if; 
     select * from `wholesale_production`.table_name where created_at >= '2012-10-01'; 
    end loop; 

    close cur1; 
end // 

delimiter ; 

call hunt();

來源

2012-10-04 JellicleCat

試試這個：

delimiter // 

drop procedure if exists hunt // 
create procedure hunt() 
begin 
    DECLARE done int default false; 
    DECLARE table_name CHAR(255); 

    DECLARE cur1 cursor for SELECT TABLE_NAME FROM INFORMATION_SCHEMA.COLUMNS 
     WHERE TABLE_SCHEMA = "wholesale_production" and COLUMN_NAME LIKE "%first%" ; 
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE; 
    open cur1; 

    myloop: loop 
     fetch cur1 into table_name; 
     if done then 
      leave myloop; 
     end if; 
     set @sql = CONCAT('select * from `wholesale_production`.', table_name, ' where created_at >= '2012-10-01'); 
     prepare stmt from @sql; 
     execute stmt; 
     drop prepare stmt; 
    end loop; 

    close cur1; 
end // 

delimiter ; 

call hunt();

來源

2012-10-04 00:26:49

我有類似的問題。如果我不關心將表名稱過濾爲LIKE'％first％''，我可以使用'SHOW TABLES'而不是'SELECT TABLE_NAME ...'嗎？ – Kal

table_name是保留名稱。應改爲不同的名稱。 –

-1

在CUR1您使用TABLE_NAME有嘗試使用該表的真實姓名

來源

2012-10-04 00:16:25

但是表格不知道，他從INFORMATION_SCHEMA獲取表名。 – Barmar

上面的一個小編輯到itertate ahtoug所有表和選擇他們。

delimiter // 
drop procedure if exists hunt // 
create procedure hunt() 
begin 
    DECLARE done int default false; 
    DECLARE table_name CHAR(255); 

    DECLARE cur1 cursor for SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES 
        WHERE table_schema ='mbu4u'; 
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE; 
    open cur1; 
     myloop: loop 
     fetch cur1 into table_name; 
     if done then 
      leave myloop; 
     end if; 
     set @sql = CONCAT('select * from `mbu4u`.',table_name); 
     prepare stmt from @sql; 
     execute stmt; 
     drop prepare stmt; 
    end loop; 

    close cur1; 
end // 

delimiter //

來源

2015-04-27 10:00:47 danielad

table_name是保留的標記在「DECLARE table_name CHAR（255）;」中使用另一個變量名稱「

來源

2017-04-26 10:35:37

MySQL循環遍歷表

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