python_reference/sqlite3/update_db.py at master · wavelets/python_reference · GitHub

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# 10/28/2013 Sebastian Raschka

# Syntax basics for updating sqlite3 data bases

import sqlite3

# make connection to existing db

conn = sqlite3.connect('zinc_db1.db')

c = conn.cursor()

# update field (no insert if id doesn't exist)

t = ('NO', 'ZINC00895033', )

c.execute("UPDATE zinc_db1 SET purchasable=? WHERE zinc_id=?", t)

print "Total number of rows changed:", conn.total_changes

# update, or insert when id does not exist

# here: updates rotatable bonds if record with primary key zinc_id exists,<br>

# else inserts new record an sets purchasable to 0

c.execute("""INSERT OR REPLACE INTO zinc_db1 (zinc_id, rotatable_bonds, purchasable)

VALUES ( 'ZINC123456798',

COALESCE((SELECT purchasable from zinc_db1 WHERE zinc_id = 'ZINC123456798'), 0)

)""")

# delete rows

t = ('NO', )

c.execute("DELETE FROM zinc_db1 WHERE purchasable=?", t)

print "Total number of rows deleted: ", conn.total_changes

# add column

c.execute("ALTER TABLE zinc_db1 ADD COLUMN 'keto_oxy' TEXT")

# save changes

conn.commit()

# print column names

c.execute("SELECT * FROM zinc_db1")

col_name_list = [tup[0] for tup in c.description]

print col_name_list

# close connection

conn.close()

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