Python基础（Day 14）(SQLite初体验)

知识点总结：

1. 使用sqlite模块完成常规sql语句执行。

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定义表格结构及数据

Name	Mobile	Birthday	isValud
Eric	18245451155	1992-09-8-18	0
Tom	18245451155	1992-01-8-07	0
Jerry	18244451155	1932-09-8-28	0
Peter	18256511575	1994-03-8-11	0
Harry	18755151255	1982-12-8-28	0

使用py自带sqlite3模块操作

# 引入模块
>>> import sqlite3
# 创建链接
>>> conn = sqlite3.connect('addressBook.db')
# 创建游标
>>> c = conn.cursor()
# 执行查询
>>> sql = "select * from LinkMan"
>>> result = c.execute(sql)
>>> result
# result为可迭代类型
<sqlite3.Cursor object at 0x000001BD5FCFD500>
>>> for row in result:
...    print(row)
    
('Eric', '18245451155', '1992-09-8-18', 0)
('Tom', '18245451155', '1992-01-8-07', 0)
('Jerry', '18244451155', '1932-09-8-28', 0)
('Peter', '18256511575', '1994-03-8-11', 0)
('Harry', '18755151255', '1982-12-8-28', 0)

# INSERT语句
>>> sql = "insert into LinkMan values ('Marry','18600098999','1985-12-02',1)"
>>> c.execute(sql)
<sqlite3.Cursor object at 0x000001BD5FCFD500>
>>> conn.commit()
>
# UPDATE语句
>>> sql = "UPDATE LinkMan SET Mobile='18833441122' where Name='Peter'"
>>> c.execute(sql)
<sqlite3.Cursor object at 0x000001BD5FCFD500>
>>> conn.commit()

# DELETE 语句
sql = "DELETE from LinkMan where rowid=5"
>>> c.execute(sql)
<sqlite3.Cursor object at 0x000001BD5FCFD500>
>>> conn.commit()
sql = "SELECT OID,* from LinkMan"
>>> c.execute(sql)
<sqlite3.Cursor object at 0x000001BD5FCFD500>

# fetchall 方法将执行结果以list形式拉取到内存
>>> lst = c.fetchall()
lst
[(1, 'Eric', '18245451155', '1992-09-8-18', 0), (2, 'Tom', '18245451155', '1992-01-8-07', 0), (3, 'Jerry', '18244451155', '1932-09-8-28', 0), (4, 'Peter', '18833441122', '1994-03-8-11', 0), (6, 'Marry', '18600098999', '1985-12-02', 1)]
for row in lst:
    print(row)
    
(1, 'Eric', '18245451155', '1992-09-8-18', 0)
(2, 'Tom', '18245451155', '1992-01-8-07', 0)
(3, 'Jerry', '18244451155', '1932-09-8-28', 0)
(4, 'Peter', '18833441122', '1994-03-8-11', 0)
(6, 'Marry', '18600098999', '1985-12-02', 1)

# fetchmany 指定条数拉取
c.execute(sql)
<sqlite3.Cursor object at 0x000001BD5FCFD500>
row = c.fetchmany(2)
row
[(1, 'Eric', '18245451155', '1992-09-8-18', 0), (2, 'Tom', '18245451155', '1992-01-8-07', 0)]

# ?参数占位符
sql = "SELECT OID,* from LinkMan where Name=?"
name = ('Tom',)
c.execute(sql,name)
<sqlite3.Cursor object at 0x000001BD5FCFD500>

# fetchone 拉取一条数据
c.fetchone()
(2, 'Tom', '18245451155', '1992-01-8-07', 0)
sql = "insert into LinkMan values(:name, :mobile,:birthday,:isvalid)

# kv方式传参，注意key与sql中定义名字需完全一致
>>> sql = "insert into LinkMan values(:name, :mobile,:birthday,:isvalid)"
>>> value_dict = {"name":"John","mobile":"17790445326","birthday":"2000-05-23","isvalid":1}
>>> c.execute(sql, value_dict)
<sqlite3.Cursor object at 0x000001BD5FCFD500>
>>> conn.commit()