fix(oracle): attempt to support MERGE on backend

Author: deepyaman

ibis/backends/oracle/__init__.py

@@ -274,6 +274,11 @@ def raw_sql(self, query: str | sg.Expression, **kwargs: Any) -> Any:
         con = self.con
         cursor = con.cursor()
 
+        # TODO(deepyaman): Refactor this hack.
+        if "MERGE" in query:
+            assert "AS " in query
+            query = query.replace("AS ", "")
+
         try:
             cursor.execute(query, **kwargs)
         except Exception:

ibis/backends/sql/__init__.py

@@ -607,10 +607,11 @@ def _build_upsert_from_table(
                 matched=True,
                 then=sge.Update(
                     expressions=[
-                        sg.column(col, quoted=quoted).eq(
-                            sg.column(col, source_alias, quoted=quoted)
+                        sg.column(col, table=target_alias).eq(
+                            sg.column(col, table=source_alias)
                         )
                         for col in columns
+                        if col != on
                     ]
                 ),
             ),
@@ -620,7 +621,7 @@ def _build_upsert_from_table(
                     this=sge.Tuple(expressions=columns),
                     expression=sge.Tuple(
                         expressions=[
-                            sg.column(col, source_alias, quoted=quoted)
+                            sg.column(col, table=source_alias)
                             for col in columns
                         ]
                     ),
@@ -629,10 +630,10 @@ def _build_upsert_from_table(
             into=sg.table(target, db=db, catalog=catalog, quoted=quoted).as_(
                 target_alias
             ),
-            using=f"({self.compile(source)}) AS {source_alias}",
-            on=sg.column(on, table=target_alias, quoted=quoted).eq(
-                sg.column(on, table=source_alias, quoted=quoted)
-            ),
+            using=f"({self.compile(source)}) {source_alias}",
+            on=sge.Paren(this=sg.column(on, table=target_alias).eq(
+                sg.column(on, table=source_alias)
+            )),
             dialect=compiler.dialect,
         )
         return query