Question

我找到了一个正确的解决方案，MySQL中的Load Data Infile如何使用On Duplicate Key Update。这是我使用的代码（从堆栈溢出中获取）：

CREATE TEMPORARY TABLE temporary_table LIKE employee_table;

SHOW INDEX FROM temporary_table;
DROP INDEX `PRIMARY` ON temporary_table;

LOAD DATA INFILE 'csv/employee_table'
INTO TABLE temporary_table FIELDS TERMINATED BY ',' LINES TERMINATED BY '\r\n' 
(
    `AutoID`, `Name`, `Age`, `Salary`
)

SHOW COLUMNS FROM employee_table;
INSERT INTO employee_table
SELECT * FROM temporary_table
ON DUPLICATE KEY UPDATE AutoID = Values(AutoID);

DROP TEMPORARY TABLE temporary_table;

上面的代码可以正常使用仅具有不同ID的新记录来更新表。但是，当PRIMARY键是自动增量（AI）时，它无法工作。它表明下面的代码不能在自动增量PRIMARY键上运行。

DROP INDEX `PRIMARY` ON temporary_table

以下是错误消息：

#1075 - Incorrect table definition; there can be only one auto column and it must be defined as a key

我很困惑，因为如果我不使用自动增量，它运行完美。有谁知道如何解决这个问题？提前谢谢。

Answer 1

有两个程序。

1）你的问题解决方案。

mysql> DROP INDEX `PRIMARY` ON test5;
ERROR 1075 (42000): Incorrect table definition; there can be only one auto column and it must be defined as a key
mysql> show create table test5;
+-------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table                                                                                                                                                                                                                             |
+-------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| test5 | CREATE TEMPORARY TABLE `test5` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(50) NOT NULL,
  `address` varchar(100) DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `name` (`name`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+-------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> alter table test5 modify `id` int(11) NOT NULL;
Query OK, 0 rows affected (0.21 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> 
mysql> DROP INDEX `PRIMARY` ON test5;
Query OK, 0 rows affected (0.02 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> 
mysql> show create table test5;
+-------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table                                                                                                                                                                                        |
+-------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| test5 | CREATE TEMPORARY TABLE `test5` (
  `id` int(11) NOT NULL,
  `name` varchar(50) NOT NULL,
  `address` varchar(100) DEFAULT NULL,
  UNIQUE KEY `name` (`name`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+-------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

2）最佳解决方案..

我们可以在程序中使用以下单个查询替换第一个（两个步骤）。

1）和2）我们可以创建具有相同参考结构且没有任何索引的新表。

CREATE TEMPORARY TABLE temporary_table SELECT * FROM target_table WHERE 1=0;

而不是..

1）创建一个新的临时表。

CREATE TEMPORARY TABLE temporary_table LIKE target_table;

2）（可选）从临时表中删除所有索引以加快速度。

SHOW INDEX FROM temporary_table; DROP INDEX PRIMARY ON temporary_table; DROP INDEX some_other_index ON temporary_table;

您也可以参考以下链接。

MySQL LOAD DATA INFILE with ON DUPLICATE KEY UPDATE

MySQL：使用AI PRIMARY密钥和重复密钥更新加载数据Infile

1 个答案: