KADB学习之操作符的使用-优快云博客

本文详细介绍了KADB（KingbaseAnalyticsDataBase）中关于SQL操作符的使用，包括比较、字符串、类型转换、逻辑和数值运算，通过实例演示如何在测试数据库中进行基本查询操作。

KADB 是北京人大金仓信息技术股份有限公司基于开源的greenplum数据库研发的一款分布式关系型数据库，全称是KingbaseAnalyticsDataBase。

学习kadb操作符的使用

连接测试数据库；

psql postgres

手动执行基本运算测试语句集；

1、创建测试表和数据

CREATE TABLE DEPARTMENT(

   ID INT PRIMARY KEY      NOT NULL,

   DEPT           CHAR(50) NOT NULL,

   EMP_ID         INT      NOT NULL

);

INSERT INTO DEPARTMENT (ID, DEPT, EMP_ID) VALUES (1, 'IT Billing', 1 );

INSERT INTO DEPARTMENT (ID, DEPT, EMP_ID) VALUES (2, 'Engineering', 2 );

INSERT INTO DEPARTMENT (ID, DEPT, EMP_ID) VALUES (3, 'Finance', 7 );

2、比较运算型

select * from department where emp_id = 1;

select * from department where emp_id != 1;

select * from department where emp_id > 1;

select * from department where emp_id < 2;

select * from department where emp_id >= 2;

select * from department where emp_id <= 2;

3、字符串型

select * from department where emp_id between 1 and 3;

select * from department where emp_id not between 1 and 3;

select * from department where emp_id in (1,2);

select * from department where emp_id not in (1,2);

select * from department where emp_id is null;

select * from department where emp_id is not null;

select * from department where exists (select emp_id from department);

select * from department where not exists (select emp_id from department);

4、类型转换型

select * from department where dept like '%Finance%';

select * from department where dept not like '%Finance%';

5、逻辑运算型

select * from department where dept = 'Engineering' and emp_id = 2;

select * from department where dept = 'Engineering' or emp_id = 1;

select * from department where emp_id not between 1 and 3;

5、数值运算型

select emp_id + 5 from department where emp_id = 1;

select emp_id - 1 from department where emp_id = 1;

select emp_id * 5 from department where emp_id = 1;

select emp_id / 1 from department where emp_id = 1;

select emp_id + (+5) from department where emp_id = 1;

select emp_id + (-5) from department where emp_id = 1;