fix: allow to add the votable field 'ident' in query_objects

this is fixed by setting an alias for the ident table in the join, so that the ambiguity is lifted with the join done by add_votable_field

Author: ManonMarchand

CHANGES.rst

@@ -149,6 +149,9 @@ simbad
   A helper method was added ``astroquery.simbad.utils.CriteriaTranslator`` to
   translate between the sim-script syntax and the TAP/ADQL syntax. [#2954]
 
+- fixed ``query_objects`` that would not work in combination with the additional field
+  ``ident`` [#3149]
+
 skyview
 ^^^^^^^
 

astroquery/simbad/core.py

@@ -90,6 +90,7 @@ class _Join:
     column_left: Any
     column_right: Any
     join_type: str = field(default="JOIN")
+    alias: str = field(default=None)
 
 
 class SimbadClass(BaseVOQuery):
@@ -670,10 +671,11 @@ def query_objects(self, object_names, *, wildcard=False, criteria=None,
         upload_name = "TAP_UPLOAD.script_infos"
         columns.append(_Column(upload_name, "*"))
 
+        # join on ident needs an alias in case the users want to add the votable field ident
         left_joins = [_Join("ident", _Column(upload_name, "user_specified_id"),
-                            _Column("ident", "id"), "LEFT JOIN"),
+                            _Column("ident", "id"), "LEFT JOIN", "ident_upload"),
                       _Join("basic", _Column("basic", "oid"),
-                            _Column("ident", "oidref"), "LEFT JOIN")]
+                            _Column("ident_upload", "oidref"), "LEFT JOIN")]
         for join in joins:
             left_joins.append(_Join(join.table, join.column_left,
                                     join.column_right, "LEFT JOIN"))
@@ -1415,7 +1417,12 @@ def _query(self, top, columns, joins, criteria, from_table="basic",
         else:
             unique_joins = []
             [unique_joins.append(join) for join in joins if join not in unique_joins]
-            join = " " + " ".join([(f'{join.join_type} {join.table} ON {join.column_left.table}."'
+            # the joined tables can have an alias. We handle the two cases here
+            join = " " + " ".join([(f'{join.join_type} {join.table} AS {join.alias} '
+                                    f'ON {join.column_left.table}."{join.column_left.name}" = '
+                                    f'{join.alias}."{join.column_right.name}"')
+                                   if join.alias is not None else
+                                   (f'{join.join_type} {join.table} ON {join.column_left.table}."'
                                     f'{join.column_left.name}" = {join.column_right.table}."'
                                     f'{join.column_right.name}"') for join in unique_joins])
 

astroquery/simbad/tests/test_simbad.py

@@ -408,9 +408,10 @@ def test_query_objects():
     # no wildcard and additional criteria
     adql = simbad.core.Simbad.query_objects(("m1", "m2"), criteria="otype = 'Galaxy..'",
                                             get_query_payload=True)["QUERY"]
-    expected = ('FROM TAP_UPLOAD.script_infos LEFT JOIN ident ON TAP_UPLOAD.script_infos.'
-                '"user_specified_id" = ident."id" LEFT JOIN basic ON basic."oid" = ident."oidref"'
-                ' WHERE (otype = \'Galaxy..\')')
+    expected = ('FROM TAP_UPLOAD.script_infos LEFT JOIN ident AS ident_upload '
+                'ON TAP_UPLOAD.script_infos.'
+                '"user_specified_id" = ident_upload."id" LEFT JOIN basic '
+                'ON basic."oid" = ident_upload."oidref" WHERE (otype = \'Galaxy..\')')
     assert adql.endswith(expected)
     # with wildcard
     adql = simbad.core.Simbad.query_objects(("M *", "NGC *"), wildcard=True, get_query_payload=True)["QUERY"]

astroquery/simbad/tests/test_simbad_remote.py

@@ -204,3 +204,10 @@ def test_add_votable_fields(self):
         simbad_instance.add_votable_fields("u")
         result = simbad_instance.query_object("HD 147933")
         assert all(filtername in result.colnames for filtername in {"u", "U", "V"})
+
+    def test_double_ident_in_query_objects(self):
+        simbad = Simbad()
+        simbad.add_votable_fields("ident")
+        result = simbad.query_objects(['HD 1'])
+        assert len(result) > 1
+        assert all(result["main_id"] == "HD      1")