Python · SQLite & XML

When should you reach for fetchmany/fetchone/iterating the cursor instead of fetchall()?

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You build an INSERT query by interpolating user input directly: ``` name = user_input sql = ("INSERT INTO suppliers " "VALUES ('%s')" % name) cur.execute(sql) ``` Why is this dangerous, and what's the fix?

You INSERT a row, then your program exits cleanly. Next run, the row is gone. ``` con = sqlite3.connect("w.db") cur = con.cursor() cur.execute("INSERT INTO t VALUES (1)") con.close() ``` What did you forget?

What's the difference between passing ":memory:" and a filename to sqlite3.connect()?

What does cursor.fetchall() return when a SELECT matches zero rows?

What does cursor.fetchone() return after the last row has already been read?

You want to insert many rows. Is this the best tool? ``` for row in rows: cur.execute( "INSERT INTO t VALUES (?,?)", row) ```

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