su - omm
gsql -r
1.创建表
CREATE TABLE customer_t
( c_customer_sk integer,
c_customer_id char(5),
c_first_name char(6),
c_last_name char(8)
) ;
2.向表中插入一条记录
–列出表中各列字段
INSERT INTO customer_t (c_customer_sk, c_customer_id, c_first_name,c_last_name) VALUES (3769, 5, 'Grace','White');
–如果已经知道表中字段的顺序，也可不列出表中的字段，和上条语法等效
INSERT INTO customer_t VALUES (3769, 5, 'Grace','White');
3.向表中插入多条记录
INSERT INTO customer_t (c_customer_sk, c_customer_id, c_first_name,c_last_name) VALUES
(6885, 1, 'Joes', 'Hunter'),
(4321, 2, 'Lily','Carter'),
(9527, 3, 'James', 'Cook'),
(9500, 4, 'Lucy', 'Baker');
4.查看数据
–查看表中记录数
select count(*) from customer_t;
–查看所有记录
select * from customer_t;
–查询表中所有c_first_name记录**
select c_first_name from customer_t;
–查询表中所有c_first_name记录，并去掉重复数据
SELECT DISTINCT(c_first_name) from customer_t;
–查询所有记录，且按c_customer_id升序排列
select * from customer_t order by c_customer_id;
–查询c_first_name为Lily的记录
select * from customer_t where c_first_name = 'Lily';
5.删除表
drop table customer_t;
INSERT INTO customer_t (c_customer_sk, c_customer_id, c_first_name,c_last_name) VALUES (3769, 5, 'Grace','White');
INSERT 0 1
INSERT INTO customer_t VALUES (3769, 5, 'Grace','White');
INSERT 0 1
INSERT INTO customer_t (c_customer_sk, c_customer_id, c_first_name,c_last_name) VALUES
(6885, 1, 'Joes', 'Hunter'),
(4321, 2, 'Lily','Carter'),
(9527, 3, 'James', 'Cook'),
(9500, 4, 'Lucy', 'Baker');
INSERT 0 4
select count(*) from customer_t;
count
-------
6
(1 row)
select * from customer_t;
c_customer_sk | c_customer_id | c_first_name | c_last_name
---------------+---------------+--------------+-------------
3769 | 5 | Grace | White
3769 | 5 | Grace | White
6885 | 1 | Joes | Hunter
4321 | 2 | Lily | Carter
9527 | 3 | James | Cook
9500 | 4 | Lucy | Baker
(6 rows)
select c_first_name from customer_t;
c_first_name
--------------
Grace
Grace
Joes
Lily
James
Lucy
(6 rows)
SELECT DISTINCT(c_first_name) from customer_t;
c_first_name
--------------
James
Grace
Lucy
Joes
Lily
(5 rows)
select * from customer_t order by c_customer_id;
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
3769 | 5 | Grace | White
3769 | 5 | Grace | White
(6 rows)
select * from customer_t where c_first_name = 'Lily';
c_customer_sk | c_customer_id | c_first_name | c_last_name
---------------+---------------+--------------+-------------
4321 | 2 | Lily | Carter
(1 row)
drop table customer_t;
DROP TABLE
课后作业
1.创建一个表products
字段名 数据类型 含义
product_id INTEGER 产品编号
product_name Char(30) 产品名
category Char(20) 种类
2.向表中插入数据，采用一次插入一条和多条记录的方式
product_id product_name category
1502 olympus camera electrncs
1601 lamaze toys
1700 wait interface Books
1666 harry potter toys
3.查询表中所有记录及记录数
4.查询表中所有category记录，并将查询结果按升序排序
5.查询表中category为toys的记录
6.删除表products
CREATE TABLE products
( product_id integer,
product_name char(30),
category char(30)
) ;
INSERT INTO products VALUES
(1502, 'olympus camera', 'electrncs');
INSERT INTO products VALUES
(1601, 'lamaze', 'toys'),
(1700, 'wait interface', 'Books'),
(1666, 'harry potter', 'toys');
select * from products;
select count(*) from products;
select category from products order by category asc;
select * from products;
drop table products;
