定义创建后变量的初始值。default_expression 必须可强制转换为data_type。 如果未指定任何默认值,则使用NULL初始化变量。 如果表达式包含一个子查询,Azure Databricks 将引发INVALID_DEFAULT_VALUE.SUBQUERY_EXPRESSION错误。 示例 SQL复制 -- Create a variable with a default>DECLAREVARIABLEmyvarINTDEFAULT5; >VALUES(...
SQL DECLARE@ListASnvarchar(max);SELECT@List= STRING_AGG(p.LastName,', ')WITHINGROUP(ORDERBYp.BusinessEntityID)FROMPerson.PersonASpWHEREp.FirstName ='William';SELECT@List; 结果集: 输出 (No column name) --- Vong, Conner, Hapke, Monroe, Richter, Sotelo, Vong, Ngoh, White, Harris, Martin...
definitions are removed when the table is dropped. Only a constant value, such as a character string; a system function, such as a SYSTEM_USER(); or NULL can be used as a default. To maintain compatibility with earlier versions of SQL Server, a constraint name can be assigned to a ...
A. Print the value of a variable initialized by using SET The following example creates the@myVarvariable, puts a string value into the variable, and prints the value of the@myVarvariable. SQL DECLARE@myVarCHAR(20);SET@myVar ='This is a test';SELECT@myVar; GO ...
EventSessionMemoryPartitionModeType EventSessionObjectName EventSessionScope EventSessionStatement EventTypeContainer EventTypeGroupContainer ExecutableEntity 可執行檔ProcedureReference ExecutableStringList ExecuteAsClause ExecuteAsFunctionOption ExecuteAsOption ExecuteAsProcedureOption ExecuteAsState...
Only a constant value, such as a character string; a system function, such as a SYSTEM_USER(); or NULL can be used as a default. To maintain compatibility with earlier versions of SQL Server, a constraint name can be assigned to a DEFAULT....
NULL Specifies the SQL value NULL, which has a null value. Examples The following procedure shows variable declarations that utilize defaults consisting of string and numeric expressions: CREATE OR REPLACE PROCEDURE dept_salary_rpt ( p_deptno NUMBER ) IS todays_date DATE := SYSDATE; rpt_title ...
The table lists command-line options (Cmd-line), options valid in configuration files (Option file), server system variables (System Var), and status variables (Status var) in one unified list, with an indication of where each option or variable is valid. If a server option set on the co...
publicstringGetQualifiedName(stringvariable); 参数 variable String 要知道其完全限定名称的变量。 返回 String 变量的限定名称,其中包括变量名以及它所属的命名空间。 示例 下面的代码示例创建一个并添加两个VariableDispenser系统变量到要读取的列表中,并将一个系统变量添加到锁定用于写入的列表。GetVariables然...
The variable registered is then accessible in SQL as "SELECT component_name.name" The variable registration needs a global of the relevant type that stores the value.To define a new variable you need to: Decide on a variable type among one of the Variable types Decide on attributes of th...