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| Deletions are marked like this. | Additions are marked like this. |
| Line 14: | Line 14: |
| conn = sqlite3.connect("/full/path/mydata.db") | sage: conn = sqlite3.connect("/full/path/mydata.db") |
| Line 21: | Line 21: |
| connection.execute("...") |
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)") |
| Line 28: | Line 27: |
| E = EllipticCurve("389a") connection.execute("...") |
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())) |
| Line 31: | Line 30: |
| This is our new entry in the database mydata! | This is our new entry in the database mydata! (If this fails with a mysterious error then possibly the entries, such as E.a1(), need to be coerced into the correct data type, such as int(E.a1()).) |
| Line 36: | Line 36: |
| {{{ sage: connection.execute("DELETE FROM elliptic_curves WHERE cremona_label = ?",("389a",)) }}} |
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| Line 39: | Line 43: |
| result = connection.execute("SELECT * FROM elliptic_curves WHERE rank = 2") result.fetchone() |
sage: result = connection.execute("SELECT * FROM elliptic_curves WHERE rank = 2") sage: result.fetchone() |
| Line 42: | Line 46: |
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! (If this fails with a mysterious error then possibly the entries, such as E.a1(), need to be coerced into the correct data type, such as int(E.a1()).)
Suppose you entered something wrong and you want to delete an entry. You use the primary key to delete an entry:
sage: connection.execute("DELETE FROM elliptic_curves WHERE cremona_label = ?",("389a",))To "query" all the elliptic curves of rank 2, type: