1. CASE语句具有如下结构 CASE SELECTOR WHEN EXPRESSION 1 THEN STATEMENT 1; WHEN EXPRESSSION 2 THEN STATEMENT 2; ... WHEN EXPRESSION N THEN STATEMENT N; ELSE STATEMENT N+1; END CASE; 保留字CASE标识CASE语句的开始。选择器决定哪个WHEN子句应该被执行。每个WHEN子句都包含一个EXPRESSION以及与之关联的...
The CASE statement can be used in the following versions of Oracle/PLSQL: Oracle 12c, Oracle 11g, Oracle 10g, Oracle 9i Example 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...
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...
#Import librariesimport cx_Oracleimport mysql.connectorimport pandas as pdfrom sqlalchemy import create_engine#Set Oralce Connectionconn = cx_Oracle.connect('test/test@192.168.19.111/orcl')#Open cursorcursor = conn.cursor()#buidling sql statement to select records from Oraclesql = "SELECT * FR...
下面来总计下之前的随笔中所说过的所有的SELECT子句的顺序。 子句 说明 是否必须使用 SELECT...
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...
它依赖于AWR,也就是说ADDM要诊断,必要要有诊断的依据。在Oracle中,这个诊断依据就是Oracle AWR,因为Oracle AWR会定期的收集整个数据库在运行期间的性能统计数据。ADDM可提供单实例以及Oracle RAC数据库级别性能诊断,它主要实现以下功能: 定期分析AWR数据(默认情况下每小时自动诊断诊断报告)...
SELECT a.c_tenantid, a.c_tacode, c_tradeacco, CASE CONCAT(CONCAT(CONCAT('F6' ,a.c_agencyno),c_taflag),a.c_businflag) WHEN '66003153' THEN ' ' ELSE c_cityno END c_cityno, a.c_fundcode, a.d_requestdate, d_requesttime, a.c_businflag, ...
如下PayAccountServiceMock类, up方法和up2方法,这2个方法使用了spring事务,逻辑是根据账户id来更新两条账户的金额。不过,两个方法更新两条账户记录的顺序是相反的。我们用后面的testcase很容易就能模拟出Oracle死锁。 package com.xxx.accounting; import org.springframework.transaction.annotation.Transactional; ...
B) Using CASE expression in a HAVING clause# Consider the followingorder_itemsandproductstables: In the following query, we use theCASEexpression in aHAVINGclause to restrict rows returned by theSELECTstatement. SELECTproduct_name, category_id,COUNT(product_id)FROMorder_itemsINNERJOINproductsUSING(pr...