oracle方法

decode('1',
'1','第1季度',
'2','第2季度',
'3','第3季度',
'4','第4季度',
'')   相当于判断

select instr('helloworld','wo') from dual; --返回结果：6    即“w”开始出现的位置  定位返回值 

ORACLE WITH AS 用法

with TT as(

select 2019 as year ,decode('1',
'1',
'第1季度',
'2',
'第2季度',
'3',
'第3季度',
'4',
'第4季度',
'') as jd
from dual
)


select * from TT

with para as
(select 2019 year, '1' jd from dual)

select (case t1.jd
when '1' then
t1.year || '03'
when '2' then
t1.year || '06'
when '3' then
t1.year || '09'
else
t1.year || '12'
end) end_month
from para t1

 NVL(Expr1,Expr2)如果Expr1为NULL，返回Expr2的值，否则返回Expr1的值

instr(:orgcode, to_char(t.aaa027)) > 0

with para as
(select 2019 year, '1' jd from dual),
get_month as (

select (case t1.jd
when '1' then
t1.year || '03'
when '2' then
t1.year || '06'
when '3' then
t1.year || '09'
else
t1.year || '12'
end) end_month
from para t1
)

(select * from para)

with as语法
相当于建了个临时表 ,或者sql的别命名

1.  
   with
2.  
   tmp1 as(select * from aa where id="001"),
3.  
   tmp2 as(select * from bb where id="001"),
4.  
   tmp3 as(select* from cc where id="001"),
5.  
   ...select *from tmp1 ,  tmp2,tmp3 ... where tmp1.id=tmp2.id=tmp3.id='001'  ;
6.  
   --相当于
7.  
   create table  tmp1  as  select * from aa
8.  
    
9.  
   create table  tmp2  as  select * from bb
10.  
     
11.  
    create table  tmp3  as  select * from cc
12.  
     
13.  
    select * from tmp1  ,tmp2,tmp3 where tmp1.id=tmp2.id=tmp3.id='001'  ;