This document provides examples of using SQLite with Python. It demonstrates how to connect to an SQLite database, execute SQL commands like CREATE TABLE and INSERT, and query the database. It also shows how to integrate SQLite with the Flask web framework, including connecting to the database within a Flask app and returning query results in JSON format. The examples cover basic CRUD (create, read, update, delete) operations and converting rows to dictionaries for JSON serialization.

1. 
Python - sqlite
Eueung Mulyana
http://eueung.github.io/python/sqlite
Python CodeLabs | Attribution-ShareAlike CC BY-SA
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2.  sqlite3
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3. Example #1
importsqlite3
conn=sqlite3.connect('example.db')
c=conn.cursor()
#-------------------------------------
c.execute('''CREATETABLEstocks
(datetext,transtext,symboltext,qtyreal,pricereal)''')
c.execute("INSERTINTOstocksVALUES('2006-01-05','BUY','RHAT',100,35.14)"
#-------------------------------------
forrowinc.execute('SELECT*FROMstocksORDERBYprice'):
printrow
#-------------------------------------
conn.commit()
conn.close()
(u'2006-01-05',u'BUY',u'RHAT',100.0,35.14)
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4. (u'2006-01-05',u'BUY',u'RHAT',100.0,35.14)
(u'2006-01-05',u'BUY',u'RHAT',100.0,35.14)
(u'2006-03-28',u'BUY',u'IBM',1000.0,45.0)
(u'2006-04-06',u'SELL',u'IBM',500.0,53.0)
(u'2006-04-05',u'BUY',u'MSFT',1000.0,72.0)
Example #2
importsqlite3
conn=sqlite3.connect('example.db')
c=conn.cursor()
#-------------------------------------
t=('RHAT',)
c.execute('SELECT*FROMstocksWHEREsymbol=?',t)
printc.fetchone()
#-------------------------------------
#Largerexamplethatinsertsmanyrecordsatatime
purchases=[('2006-03-28','BUY','IBM',1000,45.00),
('2006-04-05','BUY','MSFT',1000,72.00),
('2006-04-06','SELL','IBM',500,53.00),
]
c.executemany('INSERTINTOstocksVALUES(?,?,?,?,?)',purchas
#-------------------------------------
forrowinc.execute('SELECT*FROMstocksORDERBYprice'):
printrow
#-------------------------------------
conn.commit()
conn.close()
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5. See SQLite Python Tutorial
importsqlite3
conn=sqlite3.connect('example.db')
#first,executewithoutc=conn.cursor()
#-------------------------------------
defexecprint(strin):
res=conn.execute(strin)
forrowinres:
print"ID=",row[0]
print"NAME=",row[1]
print"ADDRESS=",row[2]
print"SALARY=",row[3],"n"
#-------------------------------------
conn.execute('''CREATETABLECOMPANY
(IDINTPRIMARYKEY NOTNULL,
NAME TEXT NOTNULL,
AGE INT NOTNULL,
ADDRESS CHAR(50),
SALARY REAL);
''')
#-------------------------------------
conn.execute("INSERTINTOCOMPANY(ID,NAME,AGE,ADDRESS,SALARY)VALUES(1,'Paul',32,'California',20000.00)"
conn.execute("INSERTINTOCOMPANY(ID,NAME,AGE,ADDRESS,SALARY)VALUES(2,'Allen',25,'Texas',15000.00)"
conn.execute("INSERTINTOCOMPANY(ID,NAME,AGE,ADDRESS,SALARY)VALUES(3,'Teddy',23,'Norway',20000.00)"
conn.execute("INSERTINTOCOMPANY(ID,NAME,AGE,ADDRESS,SALARY)VALUES(4,'Mark',25,'Rich-Mond',65000.00)"
execprint("SELECTid,name,address,salary fromCOMPANY")
Example #3
ID= 1
...
ID= 1
NAME= Paul
ADDRESS= California
SALARY= 25000.0
(1,u'Paul',u'California',25000.0)
(3,u'Teddy',u'Norway',20000.0)
(4,u'Mark',u'Rich-Mond',65000.0)
Totalnumberofrowsupdated:6
conn.execute("UPDATECOMPANYsetSALARY=25000.00whereID=1"
execprint("SELECTid,name,address,salary fromCOMPANYwher
#-------------------------------------
conn.execute("DELETEfromCOMPANYwhereID=2;")
forrowinconn.execute("SELECTid,name,address,salary fro
printrow
#-------------------------------------
print"Totalnumberofrowsupdated:",conn.total_changes
conn.commit()
conn.close()
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6.  Flask SQLite 3
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7. Example #4
importsqlite3
fromflaskimportFlask,g
#------------------------------------
DATABASE='database.db'
app=Flask(__name__)
app.config.from_object(__name__)
#------------------------------------
definit_db():
withapp.app_context():
db=get_db()
withapp.open_resource('schema.sql',mode='r')asf:
db.cursor().executescript(f.read())
db.commit()
#------------------------------------
defconnect_db():
rv=sqlite3.connect(app.config['DATABASE'])
rv.row_factory=sqlite3.Row
returnrv
#------------------------------------
defget_db():
db=getattr(g,'_database',None)
ifdbisNone:
db=g._database=connect_db()
returndb
#------------------------------------
defquery_db(query,args=(),one=False):
cur=get_db().execute(query,args)
rv=cur.fetchall()
cur.close()
return(rv[0]ifrvelseNone)ifoneelserv
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8. defseed_db():
withapp.app_context():
db=get_db()
seedusers=[('ujang',),('otong',),]
db.executemany('INSERTINTOusers(username)VALUES(?)'
#db.execute("INSERTINTOusers(username)VALUES('ujang')")
#db.execute("INSERTINTOusers(username)VALUES('otong')")
db.commit()
#------------------------------------
defprint_db():
withapp.app_context():
foruserinquery_db('select*fromusers'):
printuser['username'],'hastheid',user['id']
defprint_db_one(the_username):
withapp.app_context():
user=query_db('select*fromuserswhereusername=?'
ifuserisNone:
print'Nosuchuser'
else:
printthe_username,'hastheid',user['id']
#------------------------------------
defclose_db():
withapp.app_context():
db=getattr(g,'_database',None)
ifdbisnotNone:db.close()
#------------------------------------
init_db()
seed_db()
print_db()
print_db_one('otong')
close_db()
Example #4
ujanghastheid1
otonghastheid2
otonghastheid2
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9. Example #5
[{'username':u'ujang','id':1},{'username':u'otong','id'
127.0.0.1--[28/Nov/201515:37:09]"GET/HTTP/1.1"200-
importsqlite3
fromflaskimportFlask,g,jsonify
#------------------------------------
DATABASE='database.db'
app=Flask(__name__)
app.config.from_object(__name__)
#------------------------------------
definit_db():
#aspreviously
#------------------------------------
defmake_dicts(cur,row):
returndict((cur.description[idx][0],value)foridx,valu
defconnect_db():
rv=sqlite3.connect(app.config['DATABASE'])
#rv.row_factory=sqlite3.Row
rv.row_factory=make_dicts
returnrv
#------------------------------------
defget_db():
#aspreviously
#------------------------------------
defquery_db(query,args=(),one=False):
#aspreviously
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10. Example #5
Another Possibility (cf. JSON security)
fromflaskimportResponse
importjson
#------------------------------------
@app.route('/')
defindex():
res=query_db('select*fromusers')
returnResponse(json.dumps(res), mimetype='application/json'
@app.teardown_appcontext
defclose_connection(exception):
db=getattr(g,'_database',None)
ifdbisnotNone:
db.close()
#------------------------------------
@app.route('/')
defindex():
res=query_db('select*fromusers')
printres
returnjsonify(results=res)
#------------------------------------
if__name__=='__main__':
app.run(host='0.0.0.0',debug=True)
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11. References
sqlite3 - DB-API 2.0 - Python Documentation
Using SQLite 3 with Flask — Flask Documentation
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12. 
END
Eueung Mulyana
http://eueung.github.io/python/sqlite
Python CodeLabs | Attribution-ShareAlike CC BY-SA
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