搜索式CASE语句有个能够产生boolean(true,false,null)的搜索条件,当特定搜索条件计算结果为TRUE时,会执行与该条件相关的语句组合。搜索式CASE语句的语法如下所示: CASE WHEN SEARCH CONDIDTION 1 THEN STATEMENT 1; WHEN SEARCH CONDIDTION2 THEN STATEMENT 2; ... WHEN SEARCH CONDIDTIONN THEN STATEMENT N; EL...
SQL>show userUSER为"HR"SQL>SELECTfirst_name,last_name,department_id,2CASEdepartment_id3WHEN10THEN'Accounting'4WHEN20THEN'Sales'5WHEN30THEN'Finance'6ELSE'Other'7ENDdepartment_name8FROMemployees where rownum<2;FIRST_NAMELAST_NAMEDEPARTMENT_IDDEPARTMENT_NAME---Steven King90OtherSQL> ※测试使用的Orac...
在Oracle SQL中,CASE表达式是一种条件表达式,用于根据不同的条件返回不同的结果。它可以在SELECT语句、WHERE子句、ORDER BY子句和其他SQL语句中使用。 CASE表达式有两种形式:简单CASE表达式和搜索CASE表达式。 简单CASE表达式: 简单CASE表达式使用固定的值进行比较,并根据每个值返回不同的结果。它的语法如下: ...
In this example, if the deptno column has a 10 in it, the SQL query will return the value accounting rather than the number 10. If the deptno is not 10, 20, 30, or 40, then the CASE statement will fall through to the ELSE clause, which will return unassigned. Note that with a s...
There’s noifkeyword in SQL. If you want to doif-else-thenlogic inselect,whereor anywhere else in a statement, you need acaseexpression. This is a series ofwhenclauses that thedatabaseruns in order: For example, if you want to map exam correct percentages to grade letters according to...
Oracle中Case语句中的Select语句 sql oracle oracle-sqldeveloper SELECT (CASE WHEN T.ID = ( SELECT cte.REFERENCE FROM trans cte WHERE T.ID = CTE.PARENT_ID) THEN cte.REFERENCE ELSE null END) AS name FROM trans T 示例:我选择一个事务值作为示例。在ID=1的trans表中,然后在同一个表中我需要...
CASE表达式可以再SQL中实现if-then-else型的逻辑,9i及以上版本支持CASE表达式。 1. 使用简单CASE表达式 语法如下: CASE search_expression WHENexpression1 THEN result1 … ELSEdefault_result END store@PDB1> select product_id,product_type_id,caseproduct_type_id ...
Simple PL/SQL CASE statement A simple CASE statement evaluates a single expression and compares the result with some values. The simple CASE statement has the following structure: CASE selector WHEN selector_value_1 THEN statements_1 WHEN selector_value_1 THEN statement_2 ... ELSE else_state...
1、上表结果中的"sex"是用代码表示的,希望将代码用中文表示。可在语句中使用case语句: </>code SQL> select u.id,u.name,u.sex, (case u.sex when 1 then '男' when 2 then '女' else '空的' end )性别 from users u; ID NAME SEX 性别 ...
Oracle的CASE WHEN语法报ORA-00932错误 SELECT CASE WHEN dummy = 'x' THEN '-' ELSE 3 END FROM dual 1. 2. 3. 4. 5. 6. 上面SQL会报下面错误: ORA-00932: 数据类型不一致: 应为 CHAR, 但却获得 NUMBER 这是因为 THEN 后面是 CHAR 类型数据,而 ELSE 后面是 NUMBER 类型数据,数据类型不一致报错...