How to get a single result from a SQL query in python?

Is there an elegant way of getting a single result from an SQLite SELECT query when using Python?

for example:

conn = sqlite3.connect('db_path.db')
cursor=conn.cursor()
cursor.execute("SELECT MAX(value) FROM table")

for row in cursor:
    for elem in row:
        maxVal = elem

is there a way to avoid those nested fors and get the value directly? I've tried

maxVal = cursor[0][0]

without any success.

Solution 1:

I think you're looking for Cursor.fetchone() :

cursor.fetchone()[0]

Solution 2:

Or you could write a wrapper function that, given SQL, returns a scalar result:

def get_scalar_result(conn, sql):
    cursor=conn.cursor()
    cursor.execute(sql)

    return cursor.fetchone()[0]

I apologize for the possibly less than syntactically correct Python above, but I hope you get the idea.

Solution 3:

If you're not using pysqlite which has the built in cursor.fetchone

cursor.execute("select value from table order by value desc limit 1")

Solution 4:

Be careful, accepted answer might cause TypeError!

Due to fetchone() documentation:

Fetches the next row of a query result set, returning a single sequence, or None when no more data is available.

So with some SQL queries cursor.fetchone()[0] could turn into None[0] which leads to raising TypeError exception.

Better way to get first row or None is:

first_row = next(cursor, [None])[0]

If SQL query is empty, next will use default value [None] and get first element from that list without raising exceptions.