一、如何进入sqlite3交互模式进行命令操作?
1、确认sqlite3是否已经安装
进去python命令行,执行
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>>>
import
sqlite3
>>>
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没有报错,说明sqlite3已经成功安装了
2、如何进入sqlite3命令行
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sqlite3
/path/to/dbname
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直接执行sqlite3 加数据库名即可
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~ sqlite3 ~
/
Downloads
/
django_test
/
cmdb
/
db.sqlite3
sqlite3SQLite version
3.14
.
0
2016
-
07
-
26
15
:
17
:
14
Enter
".help"
for
usage hints.
sqlite>
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3、.tables :查看所有表
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sqlite> .tables
auth_group django_content_type
auth_group_permissions django_migrations
auth_permission django_session
auth_user ucloud_project
auth_user_groups ucloud_region
auth_user_user_permissions ucloud_uhost
django_admin_log ucloud_zone
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4、查询表中总的数据条目数
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select count()
from
TableName;
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例如:
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sqlite> select count()
from
ucloud_zone;
11
sqlite> select count()
from
ucloud_uhost;
147
sqlite> select count()
from
ucloud_project;
10
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5、执行多条查询语句
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sqlite> select
...> (select count(
1
)
from
ucloud_uhost) as uhost,
...> (select count(
1
)
from
ucloud_project) as project,
...> (select count(
1
)
from
ucloud_region) as region
...> ;
147
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10
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6、格式化输出
您可以使用下列的点命令来格式化输出为本教程下面所列出的格式:
sqlite>.header on sqlite>.mode column sqlite>.timer on sqlite>
更多命令查看:
http://www.runoob.com/sqlite/sqlite-commands.html
二、python如何执行sqlite查询命令
python执行sqlite命令的流程:
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1
、cx
=
sqlite3.connect("db.sqlite3)
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创建或打开数据库文件,如果数据库文件不存在,则创建,存在,则打开该文件。cx为数据库连接对象,它可以有以下操作: commit()--事务提交 rollback()--事务回滚 close()--关闭一个数据库连接 cursor()--创建一个游标
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2
、cursor
=
cx.cursor()
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定义了一个游标。游标对象有以下的操作: execute()--执行sql语句 executemany--执行多条sql语句 close()--关闭游标 fetchone()--从结果中取一条记录 fetchmany()--从结果中取多条记录 fetchall()--从结果中取出多条记录 scroll()--游标滚动 关于对象的方法可以去 Python 主页上查看DB API的详细文档
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3
、 cursor.execute(
"""
... select
... (select count(1) from ucloud_uhost) as uhost
... """
)
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cursor.execute(sql语句)是执行sql语句
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4
、cursor.close()
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关闭游标
下面是操作数据库的过程
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>>>
import
sqlite3
>>>
from
django.db
import
connections
cx
=
sqlite3.connect(
"/Users/cengchengpeng/Downloads/django_test/cmdb/db.sqlite3"
)
cursor
=
cx.cursor()
>>> cursor
<sqlite3.Cursor
object
at
0x10b24cb20
>
>>> cursor.execute(
"""
... select
... (select count(1) from ucloud_uhost) as uhost,
... (select count(1) from ucloud_project) as project,
... (select count(1) from ucloud_zone) as zone
... """
)
<sqlite3.Cursor
object
at
0x10b24cb20
>
>>> cursor.description
((
'uhost'
,
None
,
None
,
None
,
None
,
None
,
None
), (
'project'
,
None
,
None
,
None
,
None
,
None
,
None
), (
'zone'
,
None
,
None
,
None
,
None
,
None
,
None
))
>>> columns
=
[_[
0
].lower()
for
_
in
cursor.description]
>>> columns
[
'uhost'
,
'project'
,
'zone'
]
>>>
for
_
in
cursor:
...
print
_
...
(
147
,
10
,
11
)
>>> results
=
[
dict
(
zip
(columns, _))
for
_
in
cursor]
>>> results
>>> results
[{
'project'
:
10
,
'zone'
:
11
,
'uhost'
:
147
}]
>>> cursor.close()
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写python脚本,来执行sqlite语句
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#coding:utf-8
from
django.db
import
connections
def
open_sql_dict(sql, connection_name
=
'default'
):
dbs
=
connections[connection_name]
cursor
=
dbs.cursor()
cursor.execute(sql)
columns
=
[_[
0
].lower()
for
_
in
cursor.description]
results
=
[
dict
(
zip
(columns, _))
for
_
in
cursor]
cursor.close()
return
results
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本文转自 曾哥最爱 51CTO博客,原文链接:http://blog.51cto.com/zengestudy/1904680,如需转载请自行联系原作者