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;FIRS
2. 搜索式CASE语句 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 T...
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: ...
12 rows selected 与case when 配合: select case when grouping(e.department_id)=0 then ''||e.department_id else 'All Departments' end as department_id , case when grouping(e.job_id)=0 then e.job_id else 'All Jobs' end as job_id, avg(e.salary) from hr.employees e where e.depart...
Here’s the basic syntax of the searchedCASEstatement: CASE WHEN e1 THEN r1 [ WHEN e2 THEN r2] ... [ELSE r_else]ENDCode language:SQL (Structured Query Language)(sql) The searchedCASEexpression evaluates the Boolean expression (e1, e2, …) in eachWHENclause in the order that the Boolean...
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...
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...
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 ...
定义在测试执行过程中创建的辅助表的保存模式。 请参阅运行测试用例 (OracleToSQL)主题中的辅助表的说明。 如果选择“始终保存”,将始终存储辅助表数据,以供将来使用。 如果选择“表比较失败时保存”,则仅在发生错误时才会存储辅助表数据。 如果选择“始终删除”,将始终在执行测试之后删除辅助表。
This tutorial explains how to create a parameterized view using SQL Macros. The examples use the built-in sales history schema so there are no setup steps. Script Simple Explain Plan This script explains the plan for a query of the sh.sales and sh.products tables. Both statements must be ...