List of tables, db schema, dump etc using the Python sqlite3 API
For some reason I can't find a way to get the equivalents of sqlite's interactive shell commands:
.tables
.dump
using the Python sqlite3 API.
Is there anything like that?
In Python:
con = sqlite3.connect('database.db')
cursor = con.cursor()
cursor.execute("SELECT name FROM sqlite_master WHERE type='table';")
print(cursor.fetchall())
Watch out for my other answer. There is a much faster way using pandas.
You can fetch the list of tables and schemata by querying the SQLITE_MASTER table:
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
)
The FASTEST way of doing this in python is using Pandas (version 0.16 and up).
Dump one table:
db = sqlite3.connect('database.db')
table = pd.read_sql_query("SELECT * from table_name", db)
table.to_csv(table_name + '.csv', index_label='index')
Dump all tables:
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()
I'm not familiar with the Python API but you can always use
SELECT * FROM sqlite_master;
Here's a short and simple python program to print out the table names and the column names for those tables (python 2. python 3 follows).
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."
(EDIT: I have been getting periodic vote-ups on this, so here is the python3 version for people who are finding this answer)
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.")