在同时处理不同数据类型的值时,SQL Server一般会自动进行隐式类型转换,这种隐式类型。转换对于数据类型相近的数值是有效的,比如int和float,但是对于其他数据类型,例如整数类型和字符数据类型,这种隐式转换就无法实现了,此时必须使用显式转换。为了实现这种转换,Transact-SQL提供了两个显式转换的函数,分别是CAST()函数和...
SQL Servercomes with the following data types for storing a date or a date/time value in the database: DATE- format YYYY-MM-DD DATETIME- format: YYYY-MM-DD HH:MI:SS SMALLDATETIME- format: YYYY-MM-DD HH:MI:SS TIMESTAMP- format: a unique number ...
Creating a CLR function in SQL Server involves the following steps: Define the function as a static method of a class in a language supported by the .NET Framework. For more information about how to program functions in the common language runtime, see CLR user-defined functions. Then, compi...
Ranking Functions in SQL ServerArticle 03/24/2010 SQL Server introduced four different ranking functions either to rank records in a result-set or to rank records within groups of records of a result-set. With this inclusion we are no longer required to write several lines of code to get ...
SQL Server Advanced Functions FunctionDescription CASTConverts a value (of any type) into a specified datatype COALESCEReturns the first non-null value in a list CONVERTConverts a value (of any type) into a specified datatype CURRENT_USERReturns the name of the current user in the SQL Server...
Like functions in programming languages, SQL Server user-defined functions are routines that accept parameters, perform an action, such as a complex calculation, and return the result of that action as a value. The return value can either be a single scalar value or a result set. Benefits of...
Implementing table valued functions in Transact-SQL is easy: create function t_sql_tvfPoints() returns @points table (x float, y float) as begin insert @points values(1,2); insert @points values(3,4); return; end This is fine if your function can be done entirely in Transact-SQL. Bu...
This topic describes the change tracking functions in SQL Server 2008 and how to use them to obtain the changes that are made in a database and information about the changes. About the Change Tracking Functions Applications can use the following functions to obtain the changes that are made in...
SQL Server 2016 (13.x) and later Azure SQL Database Azure SQL Managed Instance The built-in support for JSON includes the following built-in functions described briefly in this article. ISJSONtests whether a string contains valid JSON.
A table-valued function returns a table. In SQL Server CLR integration, you can write table-valued functions in managed code.