oracle函数用法

1.with as用法（分组显示一行）

with temp as ( select er.c_employee_id,r1.c_value from XXX
where er.c_employee_id = 'xx'
)
select c_employee_id,listagg(c_value,'、') within group(order by c_employee_id ) as bb from temp
group by c_employee_id

2.case when 用法

case
when 属性 is null then
'AA'
else
属性
end

引用---WHERE CASE WHEN 用法

SELECT T2.*, T1.*
   FROM T1, T2
  WHERE (CASE WHEN T2.COMPARE_TYPE = 'A' AND
                   T1.SOME_TYPE LIKE 'NOTHING%'
                THEN 1
              WHEN T2.COMPARE_TYPE != 'A' AND
                   T1.SOME_TYPE NOT LIKE 'NOTHING%'
                THEN 1
              ELSE 0
           END) = 1