MySQL 尝试创建具有大整数的临时表失败

Question

我正在尝试创建一个临时表，将原始表中的 char(10) 数字 tkey 存储为一个无符号整数。 当它遇到第 109516 行时失败:

mysql> CREATE TEMPORARY TABLE IF NOT EXISTS lutemp AS (SELECT cast(tkey as unsigned),ca01,ce01 FROM lu);
ERROR 1264 (22003): Out of range value for column 'cast(tkey as unsigned)' at row 109516

但是如果我选择该行作为整数，那么这样做没有问题:

mysql> select cast(tkey as unsigned) from lu limit 109515,1;


+--------------------------+
| cast(tkey as unsigned) |
+--------------------------+
|               4298001000 |

+--------------------------+
1 rows in set (0.10 sec)

    

我做错了什么？

Answer 1

不要依赖数据库从 CAST(... UNSIGNED) 给你一个 BIGINT。

UNSIGNED INT 的最大值是

4,294,967,295

参见 here .你的值(value)是

4,298,001,000

尝试显式使用 BIGINT UNSIGNED:

CREATE TEMPORARY TABLE IF NOT EXISTS lutemp
(SELECT tkey, ca01,ce01 FROM lu LIMIT 0);

ALTER TABLE lutemp MODIFY tkey BIGINT UNSIGNED;

INSERT INTO lutemp (tkey, ca01,ce01)
SELECT tkey, ca01,ce01 FROM lu
;