Deprecate duplicated column names in Table definition

The :class:`_schema.Table` class now raises a deprecation warning
when columns with the same name are defined. To replace a column a new
parameter :paramref:`_schema.Table.append_column.replace_existing` was
added to the :meth:`_schema.Table.append_column` method.

The :meth:`_expression.ColumnCollection.contains_column` will now
raises an error when called with a string, suggesting the caller
to use ``in`` instead.

Co-authored-by: Federico Caselli <cfederico87@gmail.com>
Change-Id: I1d58c8ebe081079cb669e7ead60886ffc1b1a7f5

1 files changed, 17 insertions, 0 deletions

diff --git a/test/base/test_utils.py b/test/base/test_utils.py
index 843d36b71..876cb7a44 100644
--- a/test/base/test_utils.py
+++ b/test/base/test_utils.py
@@ -460,6 +460,23 @@ class ColumnCollectionCommon(testing.AssertsCompiledSQL):
         is_true(cc.contains_column(c1))
         is_false(cc.contains_column(c3))
 
+    def test_contains_column_not_column(self):
+        c1, c2, c3 = sql.column("c1"), sql.column("c2"), sql.column("c3")
+        cc = self._column_collection(columns=[("c1", c1), ("c2", c2)])
+
+        is_false(cc.contains_column(c3 == 2))
+
+        with testing.expect_raises_message(
+            exc.ArgumentError,
+            "contains_column cannot be used with string arguments",
+        ):
+            cc.contains_column("c1")
+        with testing.expect_raises_message(
+            exc.ArgumentError,
+            "contains_column cannot be used with string arguments",
+        ):
+            cc.contains_column("foo")
+
     def test_in(self):
         col1 = sql.column("col1")
         cc = self._column_collection(