Python Peewee execute_sql() example

Question

I am using the Peewee module as the ORM for my project.

I read the entire documentation, there is no clear example on how to process the result from db.execute_sql().

I traced the code, only can find db.execute_sql() return back the cursor.

Does anyone knows how to process the cursor, such as iterate over it and get back the result from complex select statement.

Update: I just found the following source code from peewee folder, it should help me to resolve this problem.

class QueryResultWrapper(object):
 """
 Provides an iterator over the results of a raw Query, additionally doing
 two things:
 - converts rows from the database into python representations
 - ensures that multiple iterations do not result in multiple queries
 """
 def __init__(self, model, cursor, meta=None):
 self.model = model
 self.cursor = cursor
 self.__ct = 0
 self.__idx = 0
 self._result_cache = []
 self._populated = False
 self._initialized = False
 if meta is not None:
 self.column_meta, self.join_meta = meta
 else:
 self.column_meta = self.join_meta = None
 def __iter__(self):
 self.__idx = 0
 if not self._populated:
 return self
 else:
 return iter(self._result_cache)
 def process_row(self, row):
 return row
 def iterate(self):
 row = self.cursor.fetchone()
 if not row:
 self._populated = True
 raise StopIteration
 elif not self._initialized:
 self.initialize(self.cursor.description)
 self._initialized = True
 return self.process_row(row)
 def iterator(self):
 while True:
 yield self.iterate()
 def next(self):
 if self.__idx self.__ct):
 try:
 self.next()
 except StopIteration:
 break

• Ayush: What is the type of the object returned? Run sql_execute() and print the result to see it's type.

Answer 1

Peewee returns a cursor. Then you can use the db-api 2 to iterate over it:

cursor = db.execute_sql('select * from tweets;')
for row in cursor.fetchall():
 print(row)
cursor = db.execute_sql('select count(*) from tweets;')
res = cursor.fetchone()
print('Total: ', res[0])

Docs: Database.execute_sql

• KJW: is there a fetch that returns a dictionary which maps column name?
• TomSawyer: @SagarShah It have to be mapped to a Class with given table name and field, how's about some query like show table status from db_name ? It maps to none table
• Mart Van de Ven: @KJW Try using the cursor.description to grab the column names: col_names = [col[0] for col in cursor.description] res = [dict(zip(col_names, row)) for row in cursor.fetchall()]