Python Flask - Easy Querying Function
Can somebody explain me the last line return (rv[0] if rv else None) if one else rv
? Especially the role of one
.
def query_db(query, args=(), one=False):
cur = g.db.execute(query, args)
rv = [dict((cur.description[idx][0], value)
for idx, value in enumerate(row)) 开发者_如何转开发for row in cur.fetchall()]
return (rv[0] if rv else None) if one else rv
one
indicates whether or not to return only a single record. If one
is true then it returns the first (rv[0]
) if there are records to be found (if rv
), otherwise it returns all the records.
By default, one
is False
, so by default the list-of-dicts generated from the fetchall
gets returned.
If you pass True
for one
, you get only the first row (turned into a dict
) of the query, or None
if the query didn't return any rows.
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