#opengauss学习的第二天
omm=# \d
List of relations
Schema | Name | Type | Owner | Storage
--------±---------±------±------±---------------------------------
public | products | table | omm | {orientation=row,compression=no}
向表中插入数据，采用一次插入一条和多条记录的方式
omm=# insert into products values(1502,‘olympus camera’,‘electrncs’);
INSERT 0 1
omm=# insert into products values(1601,‘lamaze’,‘toys’);
omm=# INSERT 0 1
omm=# insert into products values(1700,‘wait interface’,‘Books’);
INSERT 0 1
omm=# insert into products values(1666,‘harry protter’,‘toys’);
omm=# INSERT 0 1
分别获取表中一条记录、三条记录和所有记录
omm=# select * from products limit 1;
product_id | product_name | category
------------±---------------------±-------------------------------
1502 | olympus camera | electrncs
(1 row)
omm=# select * from products limit 3;
(3 rows)
omm=# product_id | product_name | category
------------±---------------------±-------------------------------
1502 | olympus camera | electrncs
1601 | lamaze | toys
1700 | wait interface | Books
omm=# select * from products ;
product_id | product_name | category
------------±---------------------±-------------------------------
1502 | olympus camera | electrncs
1601 | lamaze | toys
1700 | wait interface | Books
1666 | harry protter | toys
(4 rows)
将满足product_id > 1600的记录的product_id更新为product_id – 1000，并查看products中所有记录是否更新成功
omm=# select * from products;
product_id | product_name | category
------------±---------------------±-------------------------------
1502 | olympus camera | electrncs
1601 | lamaze | toys
1700 | harry protter | toys
1700 | wait interface | Books
(4 rows)
omm=# update products set product_id=1666 where product_name=‘harry protter’;
UPDATE 1
omm=# select * from products;
product_id | product_name | category
------------±---------------------±-------------------------------
1502 | olympus camera | electrncs
1601 | lamaze | toys
1700 | wait interface | Books
1666 | harry protter | 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 protter | toys
删除category为toys的所有记录，并查看products中数据是否删除成功
omm=# select * from products;
product_id | product_name | category
------------±---------------------±-------------------------------
1502 | olympus camera | electrncs
601 | lamaze | toys
700 | wait interface | Books
666 | harry protter | toys
(4 rows)
omm=# delete from products where category like ‘toys%’;
DELETE 2
omm=# select * from products;
product_id | product_name | category
------------±---------------------±-------------------------------
1502 | olympus camera | electrncs
700 | wait interface | Books
删除products中所有数据，并查看数据是否删除成功
select * from products;
product_id | product_name | category
------------±---------------------±-------------------------------
1502 | olympus camera | electrncs
700 | wait interface | Books
omm=# delete from products;
DELETE 2
omm=# select * from products;
omm=# product_id | product_name | category
------------±-------------±---------
删除表products
omm=# drop table products;
DROP TABLE
omm=# \d
No relations found.
