Multiple在表中的计算

　　 
　　create table myTable (
　　this　Varchar2(10),
　　that　Varchar2(10)
　　);
　　
　　insert into myTable values ('that'　　 , 'the other');
　　insert into myTable values ('confusing', 'the other');

　　insert into myTable values ('this'　　 , 'that'　　 );
　　insert into myTable values ('this'　　 , 'that'　　 );
　　insert into myTable values ('that'　　 , 'confusing');
　　insert into myTable values ('confusing', 'that'　　 );
　　insert into myTable values ('confusing', 'confusing');
　　insert into myTable values ('that'　　 , 'the other');
　　insert into myTable values ('this'　　 , 'that'　　 );
　　insert into myTable values ('confusing', 'the other');
　　
　　select
　　count(
　　case when
　　this = 'that' and
　　that = 'the other'
　　then 1
　　else null end) "Count 1",
　　count(
　　case when
　　this = 'this' and
　　that = 'that'
　　then 1
　　else null end) "Count 2",
　　count(
　　case when
　　this = 'confusing'
　　then 1
　　else null end) "Count 3"
　　from
　　myTable;

原文转自：http://www.ltesting.net