mysql - 如何在mysql中临时锁定数据库

Question

我在 MySQL 服务器上使用 InnoDB 引擎。

我有一个补丁脚本来升级我的表，例如添加新列和填充默认数据。

我想确保没有其他 session 使用该数据库。所以我需要一种方法来锁定数据库:

1. 锁不应踢出现有 session 。如果它们是任何其他现有 session ，则锁定失败并报告错误
2. 锁需要防止其他 session 读/写/更改数据库。

非常感谢大家!

Answer 1

您无需担心自己锁定表。正如 MySQL 文档 (http://dev.mysql.com/doc/refman/5.1/en/alter-table.html) 所说:

In most cases, ALTER TABLE makes a temporary copy of the original table. MySQL waits for other operations that are modifying the table, then proceeds. It incorporates the alteration into the copy, deletes the original table, and renames the new one. While ALTER TABLE is executing, the original table is readable by other sessions. Updates and writes to the table that begin after the ALTER TABLE operation begins are stalled until the new table is ready, then are automatically redirected to the new table without any failed updates.