sql中的case when的功能是实现单列或者多列的条件统计,其实Pandas也可以实现的,比如万能的apply方法,就是写起来复杂一些,没有sql case when那么直观。 apply方法可以对dataframe、series执行特定函数,其实很强大,因为python什么逻辑都可以写。 举个例子,一张考试成绩的表scores,有语文和数学的得分,现在给考生综合打分,...
CASE With Multiple Conditions It is also possible to stack multiple conditions inside a singleCASEclause. Syntax SELECTcolumn1, column2, ...CASEWHENcondition1THENresult1WHENcondition2THENresult2-- Add more WHEN conditions and results as neededENDASalias_nameFROMtable_name; We can add as manyWHEN...
在SQL语句中使用IF或CASE with multiple条件的作用是根据不同的条件执行不同的操作或返回不同的结果。这些条件可以是基于列的值、函数的结果、逻辑表达式等。 使用IF语句可以根据条件执行不同的操作。IF语句的基本语法如下: 代码语言:txt 复制 IF condition THEN statement1; ELSE statement2; END IF; 其中,conditio...
SQL语句之 case...when...then 语句 1.用简单的sql语句 SELECTdbo.tb_userinfo.user_id, dbo.tb_userinfo.user_name, dbo.tb_role.role_name, dbo.tb_userinfo.sex, dbo.tb_userinfo.phone, dbo.tb_userinfo.password, dbo.tb_userinfo.real_name, dbo.tb_userinfo.email, dbo.tb_userinfo.default1, d...
Evaluates a list of conditions and returns one of multiple possible result expressions. TheCASEexpression has two formats: The simpleCASEexpression compares an expression to a set of simple expressions to determine the result. The searchedCASEexpression evaluates a set of Boolean expressions to determin...
WHEN ESCAPE OVER WHERE EXCEPT PERCENT WHILE EXEC PIVOT WITH EXECUTE PLAN WRITETEXT 此外,ISO 标准定义了保留关键字列表。不要使用 ISO 保留关键字作为对象名和标识符。ODBC 保留关键字列表(如下表所示)与 ISO 保留关键字列表相同。 注意 ISO 标准保留关键字有时可能比 SQL Server 限制更多,有时则更少。例如...
Evaluates a list of conditions and returns one of multiple possible result expressions. The CASE expression has two formats: The simple CASE expression compares an expression to a set of simple expressions to determine the result. The searched CASE expression evaluates a set of Boolean expressions ...
DELTA_UNSUPPORTED_TIME_TRAVEL_MULTIPLE_FORMATS、 INCOMPATIBLE_JOIN_TYPES、INVALID_JOIN_TYPE_FOR_JOINWITH、INVALID_LATERAL_JOIN_TYPE、INVALID_QUERY_MIXED_QUERY_PARAMETERS、INVALID_SINGLE_VARIANT_COLUMN、MANAGED_TABLE_WITH_CRED、MUTUALLY_EXCLUSIVE_CLAUSES、NON_LAST_MATCHED_CLAUSE_OMIT_CONDITION、NON_LAST_NOT...
multiple conditional expressions in a single CASE expression. When you have multiple conditional expressions in your CASE clause, the first expression that evaluates to TRUE will be the code block that is evaluated by your TSQL statement. To better understand how the CASE expression works I will ...
If language_term is specified, the language it represents is applied to all elements of the search condition. If no value is specified, the column full-text language is used. When specified as a string, language_term corresponds to the alias column value in the sys.syslanguages (Transact-...