詳解SqlServer 表達式(expression)

更新時間：2019年11月08日 10:15:34 作者：Alan_beijing

表達式可以是單個常量，變量，列或標量函數(shù)。運算符可用于將兩個或多個簡單表達式連接到一個復雜的表達式中。這篇文章主要介紹了SqlServer 表達式(expression)的語法代碼詳解,需要的朋友可以參考下

2 具體內(nèi)容

2.1 使用范圍

SQL Server（2008開始）；Azure SQL數(shù)據(jù)庫；Azure SQL數(shù)據(jù)倉庫；并行數(shù)據(jù)倉庫

2.2 語法

是SQL Server數(shù)據(jù)庫引擎評估以獲取單個數(shù)據(jù)值的符號和運算符的組合。簡單表達式可以是單個常量，變量，列或標量函數(shù)。運算符可用于將兩個或多個簡單表達式連接到一個復雜的表達式中。

-- Syntax for SQL Server and Azure SQL Database 
{ constant | scalar_function | [ table_name. ] column | variable 
 | ( expression ) | ( scalar_subquery ) 
 | { unary_operator } expression 
 | expression { binary_operator } expression 
 | ranking_windowed_function | aggregate_windowed_function 
}
-- Syntax for Azure SQL Data Warehouse and Parallel Data Warehouse 
-- Expression in a SELECT statement 
<expression> ::= 
{ 
 constant 
 | scalar_function 
 | column 
 | variable 
 | ( expression ) 
 | { unary_operator } expression 
 | expression { binary_operator } expression 
} 
[ COLLATE Windows_collation_name ] 
-- Scalar Expression in a DECLARE, SET, IF…ELSE, or WHILE statement 
<scalar_expression> ::= 
{ 
 constant 
 | scalar_function 
 | variable 
 | ( expression ) 
 | (scalar_subquery ) 
 | { unary_operator } expression 
 | expression { binary_operator } expression 
} 
[ COLLATE { Windows_collation_name ]

2.3 參數(shù)