Offline CP calculations for OTW

A new table in the database with precalculated CP values. The data
are updated through RQ/Celery asynchronous functions

rowers/dataprepnodjango.py

@@ -489,9 +489,9 @@ def testdata(time,distance,pace,spm):
     return t1 and t2 and t3 and t4
 
 
-def getsmallrowdata_db(columns,ids=[]):
+def getsmallrowdata_db(columns,ids=[],debug=False):
 
-    data = read_cols_df_sql(ids,columns)
+    data = read_cols_df_sql(ids,columns,debug=debug)
 
     return data
         
@@ -548,6 +548,44 @@ def read_df_sql(id,debug=False):
     engine.dispose()
     return df
 
+def deletecpdata_sql(rower_id,debug=False):
+    if debug:
+        engine = create_engine(database_url_debug, echo=False)
+    else:
+        engine = create_engine(database_url, echo=False)
+
+    query = sa.text('DELETE from cpdata WHERE user={rower_id};'.format(
+        rower_id=rower_id
+        ))
+    with engine.connect() as conn, conn.begin():
+        try:
+            result = conn.execute(query)
+        except:
+            print "Database locked"
+    conn.close()
+    engine.dispose()
+
+    
+    
+def updatecpdata_sql(rower_id,delta,cp,debug=False):
+    deletecpdata_sql(rower_id,debug=debug)
+    df = pd.DataFrame(
+        {
+            'delta':delta,
+            'cp':cp,
+            'user':rower_id
+        }
+    )
+
+    if debug:
+        engine = create_engine(database_url_debug, echo=False)
+    else:
+        engine = create_engine(database_url, echo=False)
+
+    with engine.connect() as conn, conn.begin():
+        df.to_sql('cpdata', engine, if_exists='append', index=False)
+    conn.close()
+    engine.dispose()