使用Python sqlite3 API的表,db模式,转储等的列表

时间:2008-11-20 14:00:24

标签: python api sqlite dump

出于某种原因,我无法找到获得sqlite交互式shell命令等价物的方法:

.tables
.dump

使用Python sqlite3 API。

有类似的吗?

12 个答案:

答案 0 :(得分:192)

在Python中:

con = sqlite3.connect('database.db')
cursor = con.cursor()
cursor.execute("SELECT name FROM sqlite_master WHERE type='table';")
print(cursor.fetchall())

留意我的其他answer。使用pandas的方法要快得多。

答案 1 :(得分:93)

您可以通过查询SQLITE_MASTER表来获取表和模式列表:

sqlite> .tab
job         snmptarget  t1          t2          t3        
sqlite> select name from sqlite_master where type = 'table';
job
t1
t2
snmptarget
t3

sqlite> .schema job
CREATE TABLE job (
    id INTEGER PRIMARY KEY,
    data VARCHAR
);
sqlite> select sql from sqlite_master where type = 'table' and name = 'job';
CREATE TABLE job (
    id INTEGER PRIMARY KEY,
    data VARCHAR
)

答案 2 :(得分:52)

在python中执行此操作的最快方法是使用Pandas(版本0.16及更高版本)。

转储一张桌子:

db = sqlite3.connect('database.db')
table = pd.read_sql_query("SELECT * from table_name", db)
table.to_csv(table_name + '.csv', index_label='index')

转储所有表格:

import sqlite3
import pandas as pd


def to_csv():
    db = sqlite3.connect('database.db')
    cursor = db.cursor()
    cursor.execute("SELECT name FROM sqlite_master WHERE type='table';")
    tables = cursor.fetchall()
    for table_name in tables:
        table_name = table_name[0]
        table = pd.read_sql_query("SELECT * from %s" % table_name, db)
        table.to_csv(table_name + '.csv', index_label='index')
    cursor.close()
    db.close()

答案 3 :(得分:19)

我不熟悉Python API但你总是可以使用

SELECT * FROM sqlite_master;

答案 4 :(得分:17)

显然,Python 2.6中包含的sqlite3版本具有以下功能:http://docs.python.org/dev/library/sqlite3.html

# Convert file existing_db.db to SQL dump file dump.sql
import sqlite3, os

con = sqlite3.connect('existing_db.db')
with open('dump.sql', 'w') as f:
    for line in con.iterdump():
        f.write('%s\n' % line)

答案 5 :(得分:11)

这是一个简短的python程序,用于打印表名和这些表的列名(python 2. python 3如下)。

import sqlite3

db_filename = 'database.sqlite'
newline_indent = '\n   '

db=sqlite3.connect(db_filename)
db.text_factory = str
cur = db.cursor()

result = cur.execute("SELECT name FROM sqlite_master WHERE type='table';").fetchall()
table_names = sorted(zip(*result)[0])
print "\ntables are:"+newline_indent+newline_indent.join(table_names)

for table_name in table_names:
    result = cur.execute("PRAGMA table_info('%s')" % table_name).fetchall()
    column_names = zip(*result)[1]
    print ("\ncolumn names for %s:" % table_name)+newline_indent+(newline_indent.join(column_names))

db.close()
print "\nexiting."

(编辑:我一直在定期对此进行投票,所以这里是找到这个答案的人的python3版本)

import sqlite3

db_filename = 'database.sqlite'
newline_indent = '\n   '

db=sqlite3.connect(db_filename)
db.text_factory = str
cur = db.cursor()

result = cur.execute("SELECT name FROM sqlite_master WHERE type='table';").fetchall()
table_names = sorted(list(zip(*result))[0])
print ("\ntables are:"+newline_indent+newline_indent.join(table_names))

for table_name in table_names:
    result = cur.execute("PRAGMA table_info('%s')" % table_name).fetchall()
    column_names = list(zip(*result))[1]
    print (("\ncolumn names for %s:" % table_name)
           +newline_indent
           +(newline_indent.join(column_names)))

db.close()
print ("\nexiting.")

答案 6 :(得分:8)

如果有人想对熊猫做同样的事情

import pandas as pd
import sqlite3
conn = sqlite3.connect("db.sqlite3")
table = pd.read_sql_query("SELECT name FROM sqlite_master WHERE type='table'", conn)
print(table)

答案 7 :(得分:6)

如果您只想打印出数据库中的所有表和列,有些人可能会发现我的函数很有用。

在循环中,我使用 LIMIT 0 查询每个 TABLE,因此它只返回标题信息而没有所有数据。您从中创建一个空的 df,并使用可迭代的 df.columns 打印出每个列名。

conn = sqlite3.connect('example.db')
c = conn.cursor()

def table_info(c, conn):
    '''
    prints out all of the columns of every table in db
    c : cursor object
    conn : database connection object
    '''
    tables = c.execute("SELECT name FROM sqlite_master WHERE type='table';").fetchall()
    for table_name in tables:
        table_name = table_name[0] # tables is a list of single item tuples
        table = pd.read_sql_query("SELECT * from {} LIMIT 0".format(table_name), conn)
        print(table_name)
        for col in table.columns:
            print('\t' + col)
        print()

table_info(c, conn)
Results will be:

table1
    column1
    column2

table2
    column1
    column2
    column3 

etc.

答案 8 :(得分:4)

经过大量的摆弄后,我在sqlite docs找到了一个更好的答案,用于列出表格的元数据,甚至附加数据库。

meta = cursor.execute("PRAGMA table_info('Job')")
for r in meta:
    print r

关键信息是使用附件句柄名称为table_info而不是my_table添加前缀。

答案 9 :(得分:2)

查看here转储。似乎库sqlite3中有一个转储函数。

答案 10 :(得分:1)

#!/usr/bin/env python
# -*- coding: utf-8 -*-

if __name__ == "__main__":

   import sqlite3

   dbname = './db/database.db'
   try:
      print "INITILIZATION..."
      con = sqlite3.connect(dbname)
      cursor = con.cursor()
      cursor.execute("SELECT name FROM sqlite_master WHERE type='table';")
      tables = cursor.fetchall()
      for tbl in tables:
         print "\n########  "+tbl[0]+"  ########"
         cursor.execute("SELECT * FROM "+tbl[0]+";")
         rows = cursor.fetchall()
         for row in rows:
            print row
      print(cursor.fetchall())
   except KeyboardInterrupt:
      print "\nClean Exit By user"
   finally:
      print "\nFinally"

答案 11 :(得分:0)

我在PHP中实现了一个sqlite表模式解析器,你可以在这里查看:https://github.com/c9s/LazyRecord/blob/master/src/LazyRecord/TableParser/SqliteTableDefinitionParser.php

您可以使用此定义解析器来解析定义,如下面的代码:

$parser = new SqliteTableDefinitionParser;
$parser->parseColumnDefinitions('x INTEGER PRIMARY KEY, y DOUBLE, z DATETIME default \'2011-11-10\', name VARCHAR(100)');