One option is to wrap your SUM(Amount) statements in an ISNULL statement to replace NULL values with the values you want (0 in this case). Ex: SELECT ISNULL(SUM(Amount),0) FROM ... http://msdn.microsoft.com/en-us/library/ms184325(v=sql.90).aspx Thanks, Sam Lester (MSFT)...
SELECTCustomerID, AccountNumber, TerritoryIDFROMAdventureWorks.Sales.CustomerWHERETerritoryIDIN(1,2,3)ORTerritoryIDISNULL 如果在 SQL Server 将 ANSI_NULLS 设置为关闭,则可以创建使用相等运算符与 null 进行比较的表达式。 但是,不能阻止不同的连接为该连接设置 null 选项。 使用 IS NULL 测试 null 值始终有...
.Zero; SqlString descriptionValue = SqlString.Null;// Iterate through the DataTable and display the values.foreach(DataRow rowintable.Rows) {// Assign values to variables. Note that you// do not have to test for null values.idValue = (SqlInt32)row["ID"]; descriptionValue = (Sql...
有的时候为了消除NULL带来的技术债务,我们需要在 SQL 中使用IFNULL()来确保结果可控,但是这使程序变得复杂。 Null value needs a extra 1 byte to store the null information in the rows. NULL值并是占用原有的字段空间存储,而是额外申请一个字节去标注,这个字段添加了NULL约束(就像额外的标志位一样)。 As t...
SELECT CustomerID, AccountNumber, TerritoryID FROM AdventureWorks2008R2.Sales.Customer WHERE TerritoryID IN (1, 2, 3) OR TerritoryID IS NULL Transact-SQL supports an extension that allows for the comparison operators to return TRUE or FALSE when comparing against null values. This option is act...
SQL Server follows the ANSI/ISO SQL-92 specification (Section 8.2,, General rules #3) on how to compare strings with spaces. The ANSI standard requires padding for the character strings used in comparisons so that their lengths match before comparing them. The padding directly affects the semant...
SQL 通用数据类型 数据库表中的每个列都要求有名称和数据类型。Each column in a database table is required to have a name and a data type. SQL 开发人员必须在创建 SQL 表时决定表中的每个列将要存储的数据的类型。数据类型是一个标签,是便于 SQL 了解每个列期望存储什么类型的数据的指南,它也标识了 SQ...
SQL> insert into test(id, name) values(2, ''); 1 row created. SQL> insert into test(id, name) values(3, ' '); --符号中' '有一个空格 1 row created. SQL> insert into test(id, name) values(4, ' '); --符号中' '有两个空格 ...
Equal to the absence of any value. Different than zero, the empty string (""), or blank. Sorted ahead of other data. Propagated in calculations and most functions. Null values affect the behavior of commands and functions, logical expressions, and parameters. ...
in asp: Set oc = Server.CreateObject("ADODB.Connection") oc.Open "Driver={MySQL ODBC 5.1 Driver}; Server=localhost; Port=3306; Option=4; Socket=; Stmt=; Database=test; Uid=test; Pwd=test;" oc.CursorLocation = 3 strSQL = "SELECT tblInt FROM test" Set rs = oc.execute( strSQL ...