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| Deletions are marked like this. | Additions are marked like this. |
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| {{{ sage: import sqlite3 }}} |
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| This is a blank database at the moment | {{{ sage: conn = sqlite3.connect("/full/path/mydata.db") }}} |
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| This is a blank database at the moment. | |
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{{{ sage: connection.execute("CREATE TABLE cremona_label text primary key, a_0 int, a_1 int, a_2 int, a_3 int, a_4 int, a_5 int, a_6 int, rank int, regulator float)") }}} |
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This is our new entry in the database tempdb. |
{{{ sage: E = EllipticCurve("389a") sage: connection.execute("INSERT INTO elliptic_curves(cremona_label,a_0,a_1,a_2,a_3,a_4,a_5,a_6,rank,regulator) VALUES (?,?,?,?,?,?,?,?,?,?)", ("389a",0,E.a1(),E.a2(),E.a3(),E.a4(),0,E.a6(),E.rank(),E.regular())) }}} This is our new entry in the database mydata! |
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| {{{ sage: connection.execute("DELETE FROM elliptic_curves WHERE cremona_label = ?",("389a",)) |
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| will return the first one (fetchall will return all). | {{{ sage: result = connection.execute("SELECT * FROM elliptic_curves WHERE rank = 2") sage: result.fetchone() }} will return the first one (replacing "fetchone" by "fetchall" will return all). |
Tom Boothby's sqlite-tutorial
How to create a simple database in sqlite using SAGE.
In SAGE, type
sage: import sqlite3
To create a filename for the database
sage: conn = sqlite3.connect("/full/path/mydata.db")This is a blank database at the moment. Now create a table with fields labeled/typed as follows:
sage: connection.execute("CREATE TABLE cremona_label text primary key, a_0 int, a_1 int, a_2 int, a_3 int, a_4 int, a_5 int, a_6 int, rank int, regulator float)")This creates a sqlite3.cursor object. Now let's enter an entry into this database
sage: E = EllipticCurve("389a")
sage: connection.execute("INSERT INTO elliptic_curves(cremona_label,a_0,a_1,a_2,a_3,a_4,a_5,a_6,rank,regulator) VALUES (?,?,?,?,?,?,?,?,?,?)", ("389a",0,E.a1(),E.a2(),E.a3(),E.a4(),0,E.a6(),E.rank(),E.regular()))This is our new entry in the database mydata!
Suppose you entered something wrong and you want to delete an entry. You use the primary key to delete an entry: