Question

我有一个包含复合主键的表。我正在尝试从文本文件加载数据。我需要将新值添加到表的原始值。

drop table if exists load_data;

CREATE TABLE `load_data` (
  `zoneid` bigint(20) NOT NULL DEFAULT '0',
  `creativeid` bigint(20) NOT NULL DEFAULT '0',
  `count` int(11) DEFAULT NULL,
  PRIMARY KEY (`zoneid`,`creativeid`)
) ENGINE=MyISAM;

insert into load_data values (1200, 2200, 4), (9200, 9200, 91);

mysql> select * from load_data;
+--------+------------+-------+
| zoneid | creativeid | count |
+--------+------------+-------+
|   1200 |       2200 |     4 |
|   9200 |       9200 |    91 |
+--------+------------+-------+
2 rows in set (0.00 sec)

# cat abc1.txt
1200    2200    8
9200    9200    7

以下加载数据为新值添加了5个计数，而不是主键列唯一组合的原始计数。

load data infile 'abc1.txt' replace into table load_data (zoneid, creativeid, @a) set count = @a+5 ;

mysql> select * from load_data;
+--------+------------+-------+
| zoneid | creativeid | count |
+--------+------------+-------+
|   1200 |       2200 |    13 |
|   9200 |       9200 |    12 |
+--------+------------+-------+
2 rows in set (0.00 sec)

当我尝试将值添加到相应区域和广告素材ID列的原始计数值时，我得到的是NULL而不是新的总数。

mysql> load data infile 'abc1.txt' replace into table load_data (zoneid, creativeid, @a) set count = @a+@count ;
Query OK, 4 rows affected (0.00 sec)
Records: 2  Deleted: 2  Skipped: 0  Warnings: 0

mysql> select * from load_data;
+--------+------------+-------+
| zoneid | creativeid | count |
+--------+------------+-------+
|   1200 |       2200 |  NULL |
|   9200 |       9200 |  NULL |
+--------+------------+-------+
2 rows in set (0.00 sec)

预期结果：

mysql> select * from load_data;
+--------+------------+-------+
| zoneid | creativeid | count |
+--------+------------+-------+
|   1200 |       2200 |    12 |
|   9200 |       9200 |    98 |
+--------+------------+-------+

Answer 1

这是因为REPLACE强制首先删除记录。

要处理它，您可以临时添加新字段并从文件中加载count数据。然后写UPDATE表来计算count字段，然后删除temp。字段。

使用加载数据添加值

1 个答案: