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47 lines
1.2 KiB
Python
47 lines
1.2 KiB
Python
# 10/28/2013 Sebastian Raschka
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# Syntax basics for updating sqlite3 data bases
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import sqlite3
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# make connection to existing db
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conn = sqlite3.connect('zinc_db1.db')
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c = conn.cursor()
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# update field (no insert if id doesn't exist)
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t = ('NO', 'ZINC00895033', )
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c.execute("UPDATE zinc_db1 SET purchasable=? WHERE zinc_id=?", t)
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print "Total number of rows changed:", conn.total_changes
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# update, or insert when id does not exist
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# here: updates rotatable bonds if record with primary key zinc_id exists,<br>
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# else inserts new record an sets purchasable to 0
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c.execute("""INSERT OR REPLACE INTO zinc_db1 (zinc_id, rotatable_bonds, purchasable)
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VALUES ( 'ZINC123456798',
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3,
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COALESCE((SELECT purchasable from zinc_db1 WHERE zinc_id = 'ZINC123456798'), 0)
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)""")
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# delete rows
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t = ('NO', )
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c.execute("DELETE FROM zinc_db1 WHERE purchasable=?", t)
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print "Total number of rows deleted: ", conn.total_changes
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# add column
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c.execute("ALTER TABLE zinc_db1 ADD COLUMN 'keto_oxy' TEXT")
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# save changes
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conn.commit()
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# print column names
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c.execute("SELECT * FROM zinc_db1")
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col_name_list = [tup[0] for tup in c.description]
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print col_name_list
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# close connection
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conn.close()
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