Basic pySQLite example?
Use the UNIQUE keyword when creating the table, and use INSERT OR INGORE to insert only if the record is "new" (unique):
connection=sqlite3.connect(':memory:')cursor=connection.cursor()cursor.execute('CREATE TABLE foo (bar INTEGER UNIQUE, baz INTEGER)')Here we insert the row once:
cursor.execute('INSERT INTO foo (bar,baz) VALUES (?, ?)',(1,2))Trying to insert the row again fails:
try: cursor.execute('INSERT INTO foo (bar,baz) VALUES (?, ?)',(1,2))except sqlite3.IntegrityError as err: print(err) # sqlite3.IntegrityError: column bar is not uniqueINSERT OR IGNORE inserts the record only if it UNIQUE constraint is passed:
cursor.execute('INSERT OR IGNORE INTO foo (bar,baz) VALUES (?, ?)',(1,3))cursor.execute('SELECT * from foo')data=cursor.fetchall()print(data)# [(1, 2)] To create a UNIQUE index on multiple fields, use something like
cursor.execute(''' CREATE TABLE foo (bar INTEGER, baz INTEGER, bing INTEGER, UNIQUE (bar, baz))''')Here are links to info on