在Oracle数据库中,使用SELECT语句和CASE表达式可以根据特定条件返回多个列。以下是一个示例,展示了如何使用CASE表达式在SELECT语句中返回多个列: 代码语言:sql 复制 SELECT CASE WHEN condition1 THEN column1 WHEN condition2 THEN column2 ELSE column3 END AS column_alias1, CASE WHEN condition1 THEN column...
If you need to use this logic in many tables you could place it in a PL/SQL function. Then call this function in your SQL: FromOracle Database 23ai, theautomatic SQL transpilercan extract SQL expressions in PL/SQL. These are then part of the SQL statement, so at runtime it's a...
是指在Oracle数据库中,使用SELECT语句查询数据时,可以将一个SELECT语句作为子查询嵌套在另一个SELECT语句的CASE语句中。 具体来说,CASE语句是一种条件表达式,用于根据条件返回不同的结果。而子查询是指在一个查询中嵌套另一个查询,内部查询的结果作为外部查询的一部分。
The first two statements drop and recreate the LOCAL_PT_TABLE table in the Oracle database. The PL/SQL block uses the DBMS_HS_PASSTHROUGH package to execute a SELECT statement at Microsoft SQL Server and inserts the data returned into LOCAL_PT_TABLE: DROP TABLE LOCAL_PT_TABLE; CREATE TABLE...
The coalesce statement is a bit like the Oracle NVL function. Given an unlimited number of arguments, it will return the first non-null value in those arguments. Here is an example: SELECT ename, COALESCE(comm, 0) COMM FROM emp;
CASE expression syntax is similar to an IF-THEN-ELSE statement. Oracle checks each condition starting from the first condition (left to right). When a particular condition is satisfied (WHEN part) the expression returns the tagged value (THEN part). If none of the conditions are matched, the...
1ORACLE中的CASE……WHEN这两种写法查询结果不一样,请问区别在哪里?A:select sum(case when a.city_id in (47,45,35,37,36) then1 else 0 end) 甘肃北部,sum(case when a.city_id in (34,33,32) then1 else 0 end) 甘肃东部,sum(case when a.city_id in (39,38,41) then1 else 0 end)...
HOME Oracle PL/SQL PL SQL Statement Simple CASE Expression Introduction When creating selector CASE statements, you cannot have NULL in the list of possible values. In PL/SQL the Boolean expression NULL=NULL evaluates to FALSE. To fix it, wrap the selector in an NVL expression to be ...
SELECT user_name, CASE WHEN membership_level = 'Gold' THEN '8折' WHEN membership_level = 'Silver' THEN '9折' WHEN membership_level = 'Bronze' THEN '95折' ELSE '无折扣' END AS discount_rate FROM users; ``` 以上是十个使用Oracle SELECT CASE语句的示例,通过SELECT CASE语句可以根据不同的...
The CASE statement can be used in Oracle/PLSQL. You could use the CASE statement in a SQL statement as follows: (includes theexpressionclause) SELECT table_name, CASE owner WHEN 'SYS' THEN 'The owner is SYS' WHEN 'SYSTEM' THEN 'The owner is SYSTEM' ...