本程序假定:
- 您没有"_duplicate_temp_table"的副本
- 您的主键是int
- 您可以创建表
当然,这不是完美的,但在某些情况下(可能是大多数情况),它会起作用。
DELIMITER $$
CREATE PROCEDURE DUPLICATE_ROW(copytable VARCHAR(255), primarykey VARCHAR(255), copyid INT, out newid INT)
BEGIN
DECLARE EXIT HANDLER FOR SQLEXCEPTION SET @error=1;
SET @temptable = '_duplicate_temp_table';
SET @sql_text = CONCAT('CREATE TABLE ', @temptable, ' LIKE ', copytable);
PREPARE stmt FROM @sql_text;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SET @sql_text = CONCAT('INSERT INTO ', @temptable, ' SELECT * FROM ', copytable, ' where ', primarykey,'=', copyid);
PREPARE stmt FROM @sql_text;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SET @sql_text = CONCAT('SELECT max(', primarykey, ')+1 FROM ', copytable, ' INTO @newid');
PREPARE stmt FROM @sql_text;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SET @sql_text = CONCAT('UPDATE ', @temptable, ' SET ', primarykey, '=@newid');
PREPARE stmt FROM @sql_text;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SET @sql_text = CONCAT('INSERT INTO ', copytable, ' SELECT * FROM ', @temptable, '');
PREPARE stmt FROM @sql_text;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SET @sql_text = CONCAT('DROP TABLE ', @temptable);
PREPARE stmt FROM @sql_text;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SELECT @newid INTO newid;
END $$
DELIMITER ;
CALL DUPLICATE_ROW('table', 'primarykey', 1, @duplicate_id);
SELECT @duplicate_id;
max(oldtable.id) + oldtable_temp.key
的方式,这样我可以确保id递增且唯一。 - guy mograbiupdate oldtable_tem set key=2;
,而是使用update oldtable_tem set key=NULL;
,然后简单地使用insert into oldtable select * from oldtable_tem;
。 - Timofey Bugaevsky