oracle 查询的时候加条件判断

方法一.

select a.idcard,

SUM(

CASE WHEN a.subject_code=2 THEN a.SCOPE ELSE 0  END

)

,

SUM(

CASE WHEN a.subject_code=3 THEN a.SCOPE ELSE 0  END

)

,

SUM(

CASE WHEN a.subject_code=4 THEN a.SCOPE ELSE 0  END

)

,

SUM(

CASE WHEN a.subject_code=5 THEN a.SCOPE ELSE 0  END

)

from cm_student_score a

GROUP BY a. idcard

注:使用方法

SUM(

CASE WHEN a.subject_code=2 THEN a.SCOPE ELSE 0  END

)

如果a.subject_code=2则值为a.SCOPE,否则为0

而SUM()这方法是,把里面所有的成绩全部加起来.意思:所有subject_code=2的总成绩

方法二:

SELECT a.idcard,sum(DECODE(subject_code,2,SCOPE,0)) subject_code2,

sum(DECODE(subject_code,2,SCOPE,0)) subject_code3,

sum(DECODE(subject_code,2,SCOPE,0)) subject_code4,

sum(DECODE(subject_code,2,SCOPE,0)) subject_code5

from cm_student_score  GROUP BY a. idcard

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2import java.util.logging.Level;

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6 * Title: JDBC连接数据库

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9public class JDBCExampl ......

Exam Number/Code : 1Z0-053

Exam Name : Oracle Database 11g: Administration II

Questions and Answers : 167 Q&As

Update Time: 2010-05-15

1. You are not sure if Flashback Database is enabled. What database column and view can you query to

see if the flashback logs are being created in the ......

1、 停止oracle所有的服务(开始--运行--输入services.msc)

2、 删除注册表上的ORACLE的有关键值(开始-->运行-->输入regedit)将HKEY_LOACAL_MACHINE/SOFTWARE下的主键ORACLE全部删除。

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虽然这是我找到最详细的配置描述，但是尝试还是没有成功。

1.下载Oracle Client Package

.

从

http://www.oracle.com/technology/software/tech/oci/instantclient/htdocs/winsoft.html

下载

Instant

Client Package – Basic

包

(

标注

:All files

required to run OCI, OCCI, and JDBC-OC ......

虽然这是我找到最详细的配置描述，但是尝试还是没有成功。

1.下载Oracle Client Package

.

从

http://www.oracle.com/technology/software/tech/oci/instantclient/htdocs/winsoft.html

下载

Instant

Client Package – Basic

包

(

标注

:All files

required to run OCI, OCCI, and JDBC-OC ......