果然,用了SUM函数之后,SQL语句变简单了,效率也大大提高了! SELECTdate,SUM(caseresultwhen'win'then1else0end)ASwin,SUM(caseresultwhen'lose'then1else0end)ASloseFROMinfoGROUPBYdateORDERBYdate; 测试完了,删除测试表: DROPTABLEinfo; 参考资料: http://www
Then the corresponding value would be returned by the CASE function.Example - Excludes expression You could use the CASE function in a SQL statement where the expression is omitted. SELECT CASE WHEN a < b THEN 1 WHEN supplier_type = 'clothing' THEN 2 ELSE 3 END FROM suppliers; In this ...
The SQL CASE Expression TheCASEexpression goes through conditions and returns a value when the first condition is met (like an if-then-else statement). So, once a condition is true, it will stop reading and return the result. If no conditions are true, it returns the value in theELSE...
SQL USEAdventureWorks2022; GOCREATEFUNCTIONdbo.GetContactInformation (@BusinessEntityIDINT)RETURNS@retContactInformationTABLE( BusinessEntityIDINTNOTNULL, FirstNameNVARCHAR(50)NULL, LastNameNVARCHAR(50)NULL, ContactTypeNVARCHAR(50)NULL, PRIMARYKEYCLUSTERED (BusinessEntityIDASC) )AS-- Returns the first name...
执行此T-Sql,报错:Error converting data type nvarchar to float. 3.我们使用同样的Table,只是稍微改动Value,结果如下: TestTable 执行此T-Sql,我们会得到同样的错误。 针对上面这个问题,我们最终找到的问题是: 使用Case语句时,前后的数据类型不匹配造成的,不管你实际的结果是不是完全满足最终你想要的格式,在Case...
T-SQL 101: The CASE FunctionNoncorresponding MovieReview records are represented by NULL values. Because this code is filtering the records to show only reviews conducted by the employee whose ID is I, you have to include the code OR EmployeeID IS NULL in the WHERE clause....
问Postgres错误:在CASE中不允许使用set返回函数ENSELECT 表名称.*,CASE WHEN ujz.字段名=1 THEN ...
表语句： DROP TABLE IF EXISTS `yj_item_plan`; CREATE TABLE `yj_item_plan` ( `id` big...
or a customer. The function returns the first and last name of a givenBusinessEntityIDand the contact type for that person. TheCASEexpression in the SET statement determines the value to display for the columnContactTypebased on the existence of theBusinessEntityIDcolumn in theEmployee,Vendor, ...
Using the COALESCE function 5.Use COALESCE to print the mobile number. Use the number '07986 444 2266' if there is no number given. Show teacher name and mobile number or '07986 444 2266' 使用COALESCE打印手机号码。 如果没有给出数字,则使用数字“ 07986 444 2266”。 显示老师的姓名和手机号码...