On Sat, Oct 14, 2017 at 1:43 AM, boB Stepp <robertvst...@gmail.com> wrote:
> I am currently trying to make the following work: > > py3: tb_exists = c.execute('select name from sqlite_master where > type="table"') > > so that I can embed this in an if statement. But it is not behaving > quite like I hope yet. So I am still experimenting and Googling ... I'm tired and not thinking clearly anymore, but I think I have something to give me the basis of what I want to do. First, what happens if the table does *not* exist: py3: import sqlite3 py3: conn = sqlite3.connect(':memory:') py3: c = conn.cursor() py3: tb_exists = "select name from sqlite_master where type='table' and name='test'" py3: tb_ck = c.execute(tb_exists).fetchone() py3: tb_ck py3: print(tb_ck) None So I get "None" as a result if the target table has not been created yet. But if I *do* create the table I want: py3: with open('create_sqlite3_db.sql') as f: ... sql = f.read() ... py3: c.executescript(sql) <sqlite3.Cursor object at 0x00000000026B4490> py3: tb_exists = "select name from sqlite_master where type='table' and name='BloodPressureReadings'" py3: tb_ck = c.execute(tb_exists).fetchone() py3: print(tb_ck) ('BloodPressureReadings',) So it is looking like I can use this technique to determine if I need to create the BloodPressureReadings table or not. Am I on track here or is there a better technique? -- boB _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor