Understanding Application Engine Meta-SQL
理解应用引擎元SQL
Application Engine meta-SQL is divided into the following categories:
应用引擎元SQL分为以下几类：
- Construct
- 构造
construct is a direct substitution of a value that helps to build or modify a SQL statement.
构造是值的直接替代，有助于构建或修改SQL语句。
- Function
- 功能
function performs an action on its own or causes another function to be called.
一个函数自己执行一个动作，或者导致另一个函数被调用。
- Meta-variable
- 元变量
A meta-variable allows substitution of text within SQL statements.
Note: Some meta-SQL elements can be used only in Application Engine programs, some can be used both in Application Engine programs and in other environments, and some cannot be used in Application Engine programs at all. This PeopleBook discusses only meta-SQL elements that can be used in Application Engine. You can find a complete reference to all PeopleSoft meta-SQL elements in PeopleCode Language Reference.
注意:有些元SQL元素只能在Application Engine程序中使用，有些既可以在Application Engine编程中使用，也可以在其他环境中使用，还有一些根本不能在Application Engine程序中使用。本PeopleBook仅讨论可以在应用程序引擎中使用的元SQL元素。您可以在PeopleCode Language Reference中找到对所有PeopleSoft元SQL元素的完整引用。
Related Links
++Using Application Engine Meta-SQL++
"Understanding Meta-SQL" (PeopleCode Language Reference)
使用应用程序引擎Meta-SQL的相关链接
"理解元数据库"（PeopleCode语言参考）