MySQL没有一个像MSSQL的客户端去管理，所以有了phpMyAdmin，管理MySQL不再单纯依靠命令行，但phpMyAdmin似乎不是那么万能，偶尔也
MySQL没有一个像MSSQL的客户端去管理，所以有了phpMyAdmin，管理MySQL不再单纯依靠命令行，但phpMyAdmin似乎不是那么万能，偶尔也会耍耍版本细节的脾气。
最近使用MySQL触发器，不想使用命令行编辑，但phpMyAdmin调试缺比较麻烦，原来想的是先建立一个空的触发器，然后修改，后来发现修改迁移问题多的要死，在老王同学的帮助下，经过几个晚上努力，整理出一些规律。
调试的时候，可以在空的触发器上逐条增加语句，一点一点调试，这样很容易定位问题，迅速修改。
迁移的时候，不能直接编辑触发器拷贝里边的代码，，我用的phpMyAdmin是2.11.9*版本的，生成的代码虽然他自己认，但一迁移就出了问题，我还没去阅读phpMyAdmin的代码，不知道代码如何产生，但begin end里的内容大致相同，不同的是两头的辅助语句。
两头的内容跟版本密切相关，用MySQLdump导出的语句做模板，把过程添加到里边，基本就没什么问题了。
不同版本的语法稍有出入，没有详细总结，总之掌握了调试的方法，解决问题速度就会提升。
使用触发器后，原来十几次的交互，一次就可以解决。我尝试了下出发器和存储过程，发现开发成本都差不多，复杂度也是类似的，所以没有用存储过程。
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Explain the role of InnoDB redo logs and undo logs.Apr 15, 2025 am 12:16 AMInnoDB uses redologs and undologs to ensure data consistency and reliability. 1.redologs record data page modification to ensure crash recovery and transaction persistence. 2.undologs records the original data value and supports transaction rollback and MVCC.
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What is the Using temporary status in EXPLAIN and how to avoid it?Apr 15, 2025 am 12:14 AMUsingtemporary indicates that the need to create temporary tables in MySQL queries, which are commonly found in ORDERBY using DISTINCT, GROUPBY, or non-indexed columns. You can avoid the occurrence of indexes and rewrite queries and improve query performance. Specifically, when Usingtemporary appears in EXPLAIN output, it means that MySQL needs to create temporary tables to handle queries. This usually occurs when: 1) deduplication or grouping when using DISTINCT or GROUPBY; 2) sort when ORDERBY contains non-index columns; 3) use complex subquery or join operations. Optimization methods include: 1) ORDERBY and GROUPB
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