1.登录数据库
Welcome to 墨天轮.
This is Web Terminal of modb.pro; Good Good Study, Day Day Up.
root@modb:~# su - omm
omm@modb:~$ gsql -r
gsql ((openGauss 2.0.0 build 78689da9) compiled at 2021-03-31 21:03:52 commit 0 last mr )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.
2.创建表
omm=# CREATE TABLE customer_t
omm-# ( c_customer_sk integer,
omm(# c_customer_id char(5),
omm(# c_first_name char(6),
omm(# c_last_name char(8)
omm(# ) ;
CREATE TABLE
3.插入表数据
omm=# INSERT INTO customer_t VALUES
omm=# (6885, 1, 'Joes', 'Hunter'),
omm=# (4321, 2, 'Lily','Carter'),
omm=# (9527, 3, 'James', 'Cook'),
omm=# (9500, 4, 'Lucy', 'Baker');
INSERT 0 4
4.查看表数据
omm=# select * from customer_t;
c_customer_sk | c_customer_id | c_first_name | c_last_name
---------------+---------------+--------------+-------------
6885 | 1 | Joes | Hunter
4321 | 2 | Lily | Carter
9527 | 3 | James | Cook
9500 | 4 | Lucy | Baker
(4 rows)
5.查看表2条数据
omm=# select * from customer_t limit 2;
c_customer_sk | c_customer_id | c_first_name | c_last_name
---------------+---------------+--------------+-------------
6885 | 1 | Joes | Hunter
4321 | 2 | Lily | Carter
(2 rows)
6.查看表c_first_name列并显示列名为c_name
omm=# select c_first_name as c_name from customer_t;
c_name
--------
Joes
Lily
James
Lucy
(4 rows)
7.将表customer_t的表的c_customer_id列全部加100
omm=# update customer_t set c_customer_id = c_customer_id + 100;
UPDATE 4
8.查看customer_t表数据
omm=# select * from customer_t;
9527 | 103 | James | Cook
9500 | 104 | Lucy | Baker
6885 | 101 | Joes | Hunter
4321 | 102 | Lily | Carter
(4 rows)
9. 将表customer_t的表的c_customer_sk 小于5000的c_customer_sk 全部*2倍
update customer_t set c_customer_sk = c_customer_sk * 2 where c_customer_sk < 5000;
UPDATE 1
omm=# select * from customer_t;
c_customer_sk | c_customer_id | c_first_name | c_last_name
---------------+---------------+--------------+-------------
6885 | 101 | Joes | Hunter
9527 | 103 | James | Cook
9500 | 104 | Lucy | Baker
8642 | 102 | Lily | Carter
(4 rows)
10.删除c_first_name为Lucy的customer_t表数据
omm=# delete from customer_t where c_first_name = 'Lucy';
DELETE 1
omm=# select * from customer_t;
omm=# c_customer_sk | c_customer_id | c_first_name | c_last_name
---------------+---------------+--------------+-------------
6885 | 101 | Joes | Hunter
9527 | 103 | James | Cook
8642 | 102 | Lily | Carter
(3 rows)
11.删除所有customer_t表数据
omm=# delete from customer_t;
DELETE 3
omm=# select * from customer_t;
c_customer_sk | c_customer_id | c_first_name | c_last_name
---------------+---------------+--------------+-------------
(0 rows)
12.删除customer_t表
omm=# drop table customer_t;
DROP TABLE
作业
omm=# create table products(product_id integer,product_name char(20),category char(30));
CREATE TABLE
omm=# insert into products values(1502,'olympus camera','electrncs');
INSERT 0 1
omm=# insert into products values(1601,'lamaze','toys'),(1700,'wait interface','Books'),(1666,'harry potter','toys');
INSERT 0 3
omm=# select * from products limit 1;
product_id | product_name | category
------------+----------------------+--------------------------------
1502 | olympus camera | electrncs
(1 row)
omm=# select * from products limit 3;
product_id | product_name | category
------------+----------------------+--------------------------------
1502 | olympus camera | electrncs
1601 | lamaze | toys
1700 | wait interface | Books
(3 rows)
omm=# select * from products;
product_id | product_name | category
------------+----------------------+--------------------------------
1502 | olympus camera | electrncs
1601 | lamaze | toys
1700 | wait interface | Books
1666 | harry potter | toys
(4 rows)
omm=# update products set product_id=product_id-1000 where product_id>1600;
UPDATE 3
omm=# select * from products;
product_id | product_name | category
------------+----------------------+--------------------------------
1502 | olympus camera | electrncs
601 | lamaze | toys
700 | wait interface | Books
666 | harry potter | toys
(4 rows)
omm=# delete from products where category='toys';
DELETE 2
omm=# select * from products;
product_id | product_name | category
------------+----------------------+--------------------------------
1502 | olympus camera | electrncs
700 | wait interface | Books
(2 rows)
omm=# delete from products;
DELETE 2
omm=# drop table products;
DROP TABLE
omm=#
omm=#
omm=#
愉快学习的第二天结束！！！加油！
