操作符

求差集操作符：MINUS

vastbase=# select * from dept 
vastbase-# minus
vastbase-# select * from dept where deptno=10;
deptno |   dname    |   loc   
--------+------------+---------
 30 | SALES      | CHICAGO
 20 | RESEARCH   | DALLAS
 40 | OPERATIONS | BOSTON
(3 rows)

不等于操作符：^=

vastbase=#  select 1^=1 from dual;
?column? 
----------
f
(1 row)

时间 + 整数操作符：date + int

vastbase=# select sysdate,sysdate+1;
   sysdate       |      ?column?       
---------------------+---------------------
2020-09-25 15:24:48 | 2020-09-26 15:24:48
(1 row)

时间 - 整数操作符：date – int

vastbase=# select sysdate,sysdate-1;
   sysdate       |      ?column?       
---------------------+---------------------
2020-09-25 15:25:56 | 2020-09-24 15:25:56
(1 row)

时间与字符的比较

vastbase=# select sysdate>'2020-05-17'::text,sysdate;
?column? |       sysdate       
----------+---------------------
t        | 2020-09-25 15:28:00
(1 row)
vastbase=# select sysdate>='2020-05-17'::text,sysdate;
?column? |       sysdate       
----------+---------------------
t        | 2020-09-25 15:28:56
(1 row)

vastbase=# select sysdate<'2020-05-17'::text,sysdate;
?column? |       sysdate       
----------+---------------------
f        | 2020-09-25 15:29:09
(1 row)

vastbase=#  select sysdate<='2020-05-17'::text,sysdate;
?column? |       sysdate       
----------+---------------------
f        | 2020-09-25 15:29:20
(1 row)

vastbase=# select sysdate='2020-05-17'::text,sysdate;
?column? |       sysdate       
----------+---------------------
f        | 2020-09-25 15:29:31
(1 row)

时间 - 时间操作符：date – date

vastbase=# select sysdate-(sysdate-11);
?column? 
----------
11 days
(1 row)

数值类型+/- 字符操作符

select 1::int+'1'::text;
select 1::smallint+'1'::text;
select 1::bigint-'1'::text;
select 1::int-'1'::text;
select 1::smallint-'1'::text;
select 1.1::float+'1'::text;
select 1.1::double precision+'1'::text;
select 1.1::number+'1'::text;
select 1.1::float-'1'::text;
select 1.1::double precision-'1'::text;
select 1.1::number-'1'::text;

执行如下：

vastbase=# select 1::int+'1'::text; 
?column? 
----------        
      2
(1 row)
vastbase=# select 1::smallint+'1'::text; 
?column? 
----------        
      2
(1 row)
vastbase=# select 1::bigint-'1'::text; 
?column?
----------        
      0
(1 row)
vastbase=# select 1::int-'1'::text; 
?column?
----------        
      0
(1 row)
vastbase=# select 1::smallint-'1'::text; 
?column? 
----------
      0
(1 row)
vastbase=# select 1.1::float+'1'::text; 
?column? 
----------
  2.1
(1 row)vastbase=# select 1.1::double precision+'1'::text; 
?column? 
----------
  2.1
(1 row)vastbase=# select 1.1::number+'1'::text; 
?column? 
----------
  2.1
(1 row)
vastbase=# select 1.1::float-'1'::text; 
?column? 
----------
   .1
(1 row)
vastbase=# select 1.1::double precision-'1'::text; 
?column?
----------
    .1
(1 row)
vastbase=# select 1.1::number-'1'::text; 
?column? 
----------
   .1
(1 row)

数值类型 *、/ 字符操作符

select 3::smallint/'2'::text;
select 3::bigint/'2'::text;
select 3::int/'2'::text;
select 3::int*'2'::text;
select 3::bigint*'2'::text;
select 3::smallint*'2'::text;
select 3.8::float/'2'::text;
select 3.8::double precision /'2'::text;
select 3.8::number /'2'::text;

vastbase=# select 3::smallint/'2'::text;
?column? 
----------
  1.5
(1 row)
vastbase=# select 3::bigint/'2'::text;
?column? 
----------
  1.5
(1 row)

vastbase=# select 3::int/'2'::text;
?column? 
----------
  1.5
(1 row)

vastbase=# select 3::int*'2'::text;
?column? 
----------
    6
(1 row)

vastbase=# select 3::bigint*'2'::text;
?column? 
----------
    6
(1 row)

vastbase=# select 3::smallint*'2'::text;
?column? 
----------
    6
(1 row)

vastbase=# select 3.8::float/'2'::text;
?column? 
----------
  1.9
(1 row)

vastbase=# select 3.8::double precision /'2'::text;
?column? 
----------
  1.9
(1 row)

vastbase=# select 3.8::number /'2'::text;
?column?
----------
  1.9
(1 row)

数值型与字符型的比较

select 1='1'::text;
select 10='1'::text;
select 10>'1'::text;
select 10>='1'::text;
select 10<='1'::text;
select 10<'1'::text;
select 10<>'1'::text;
select 10::float <>'1'::text;
select 10::float >'1'::text;
select 10::float >='1'::text;
select 10::float <='1'::text;
select 10::float <'1'::text;

vastbase=# select 1='1'::text;
?column? 
----------
t
(1 row)

vastbase=# select 10='1'::text;
?column? 
----------
f
(1 row)

vastbase=# select 10>'1'::text;
?column? 
----------
t
(1 row)

vastbase=# select 10>='1'::text;
?column? 
----------
t
(1 row)

vastbase=# select 10<='1'::text;
?column? 
----------
f
(1 row)

vastbase=# select 10<'1'::text;
?column? 
----------
f
(1 row)

vastbase=# select 10<>'1'::text;
?column? 
----------
t
(1 row)

vastbase=# select 10::float <>'1'::text;
?column? 
----------
t
(1 row)

vastbase=# select 10::float >'1'::text;
?column? 
----------
t
(1 row)

vastbase=# select 10::float >='1'::text;
?column? 
----------
t
(1 row)

vastbase=# select 10::float <='1'::text;
?column? 
----------
f
(1 row)

vastbase=# select 10::float <'1'::text;
?column? 
----------
f
(1 row)

连接操作符||

vastbase=# select empno||ename from emp;  
?column?  
------------ 
7369SMITH 
7499ALLEN 
7521WARD 
7566JONES 
7654MARTIN 
7698BLAKE 
7782CLARK 
7839KING 
7844TURNER 
7900JAMES 
7902FORD 
7934MILLER
(12 rows)

VastbaseG100

操作符

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