类型检查函数 (Azure Cosmos DB)Type checking functions (Azure Cosmos DB)

适用于: SQL API

使用类型检查函数可以检查 SQL 查询中表达式的类型。The type-checking functions let you check the type of an expression within a SQL query. 当项中的属性可变或未知时,可以使用类型检查函数即时确定这些属性的类型。You can use type-checking functions to determine the types of properties within items on the fly, when they're variable or unknown.

函数Functions

下表列出了支持的内置类型检查函数:Here's a table of supported built-in type-checking functions:

以下函数支持对输入值进行类型检查,并且每个都会返回一个布尔值。The following functions support type checking against input values, and each return a Boolean value.

后续步骤Next steps