对于基于sql的数据库:

Not taking advantage of CLUSTERED INDEXES or choosing the wrong column(s) to CLUSTER. Not using a SERIAL (autonumber) datatype as a PRIMARY KEY to join to a FOREIGN KEY (INT) in a parent/child table relationship. Not UPDATING STATISTICS on a table when many records have been INSERTED or DELETED. Not reorganizing (i.e. unloading, droping, re-creating, loading and re-indexing) tables when many rows have been inserted or deleted (some engines physically keep deleted rows in a table with a delete flag.) Not taking advantage of FRAGMENT ON EXPRESSION (if supported) on large tables which have high transaction rates. Choosing the wrong datatype for a column! Not choosing a proper column name. Not adding new columns at the end of the table. Not creating proper indexes to support frequently used queries. creating indexes on columns with few possible values and creating unnecessary indexes. ...more to be added.

不了解数据库并发模型以及它如何影响开发。事后添加索引和调整查询很容易。然而，应用程序的设计没有适当考虑热点，资源争用 和正确的操作(假设您刚刚阅读的内容仍然有效!)可能需要在数据库和应用层中进行重大更改，以便稍后纠正。

如果您正在使用复制(MySQL)，以下函数是不安全的，除非您正在使用基于行的复制。

USER(), CURRENT_USER() (or CURRENT_USER), UUID(), VERSION(), LOAD_FILE(), and RAND()

参见:http://dev.mysql.com/doc/refman/5.1/en/replication-features-functions.html

a)在字符串中硬编码查询值 b)将数据库查询代码放在Windows窗体应用程序的“OnButtonPress”操作中

两者我都见过。

忘记在表之间建立关系。我记得当我刚开始在我现在的雇主工作时，我不得不清理这些东西。

在运行DELETE查询之前没有执行相应的SELECT查询(特别是在生产数据库上)!