diff --git a/pycen/tools.py b/pycen/tools.py
index 0ecfd9b..7160e98 100644
--- a/pycen/tools.py
+++ b/pycen/tools.py
@@ -10,6 +10,22 @@ from pandas import Series, Index, read_sql, merge
 
 
 
+#####################################
+###      Fonctions connexion      ###
+#####################################
+def __get_pkey__(engine,table_name,schema):
+  pk = engine.dialect.get_pk_constraint(engine,table_name=table_name,schema=schema)
+  return pk
+
+
+def __get_dtype__(engine,table_name,schema):
+  cols = engine.dialect.get_columns(engine,table_name=table_name,schema=schema)
+  # name_cols = [i['name'] for i in cols]
+  # type_cols = [i['type'] for i in cols]
+  type_cols = {i['name']:i['type'] for i in cols}
+  return type_cols
+
+
 #####################################
 ###      Fonctions générales      ###
 #####################################
@@ -87,6 +103,13 @@ def _get_table(con, schema, table, ids=None, nom=None, cols=None, params_col={},
     'history'; A une Date_fin 
     'all'; Tous les Sites
   '''
+  pkey = __get_pkey__(con,table,schema)
+  if pkey['constrained_columns']:
+    pk = pkey['constrained_columns']
+    if len(pk)==1: pk = pk[0]
+    else: raise ValueError(pk)
+  else : pk = 'site_code'
+
   sql = 'SELECT * FROM {sch}.{tab}'.format(sch=schema, tab=table)
   if params_col:
     params_col = { k: v for k, v in params_col.items() if v }
@@ -94,7 +117,7 @@ def _get_table(con, schema, table, ids=None, nom=None, cols=None, params_col={},
   if cols : sql = sql.replace('*', to_colStringSQL(cols) )
   # Si arg (ids|nom|params_col), ajout de 'WHERE'
   if ids or nom or params_col or (statut!='all' and table=='sites') : sql = sql + ' WHERE '
-  if ids : sql = sql + 'id IN %(ids)s'
+  if ids : sql = sql + pk +' IN %(ids)s'
   if ids and (nom or params_col or (statut!='all' and table=='sites')) : sql = sql + ' AND '
   if nom : sql = sql + 'nom IN %(nom)s'
   if nom and (params_col or (statut!='all' and table=='sites')) : sql = sql + ' AND '
@@ -114,7 +137,7 @@ def _get_table(con, schema, table, ids=None, nom=None, cols=None, params_col={},
     df = _set_geom(df)
   return df
 
-def _set_geom(df, hex=True):
+def _set_geom(df, hex=True, crs=2154):
   from shapely.wkb import loads
   import geopandas as gpd         # set_geometry
 
@@ -122,10 +145,10 @@ def _set_geom(df, hex=True):
     # df['geometry'] = [(loads(geom, hex=hex)) for geom in df['geom']]
     geometry = [(loads(geom, hex=hex)) for geom in df['geom']]
     df.drop(columns=['geom'], inplace=True)
-    df = gpd.GeoDataFrame(df,geometry=geometry,crs='EPSG:2154')
+    df = gpd.GeoDataFrame(df,geometry=geometry,crs='EPSG:%s'%crs)
     df.rename_geometry('geom', inplace=True)
   else:
-    df = df.set_geometry('geom', crs='EPSG:2154')
+    df = df.set_geometry('geom', crs='EPSG:%s'%crs)
   
   return df
 
@@ -369,13 +392,17 @@ def calc_recouvrmt(df1,df2):
   return df1
 
 
-def Polygons_to_MultiPolygon(df):
+def Polygons_to_MultiPolygon(df,geom_col=None):
   from shapely.geometry import MultiPolygon
   from pandas import concat
+  
+  if not geom_col:
+    geom_col = df.geometry.name
+
   df = df.copy()
   multi = df.loc[df.geom_type=='MultiPolygon'].copy()
   poly = df.loc[df.geom_type=='Polygon'].copy()
-  poly['geom'] = [MultiPolygon([geom]) for geom in df.loc[df.geom_type=='Polygon','geom'] ]
+  poly[geom_col] = [MultiPolygon([geom]) for geom in df.loc[df.geom_type=='Polygon',geom_col] ]
   df = concat([multi,poly])
   df.sort_index(inplace=True)
   return df
\ No newline at end of file