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Fix: MSSQL merge should handle all columns being unique keys #4842

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Merged
treysp merged 1 commit into from
Jun 30, 2025
+43 −15
Merged

Fix: MSSQL merge should handle all columns being unique keys #4842

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32 changes: 17 additions & 15 deletions sqlmesh/core/engine_adapter/mssql.py
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Original file line number Diff line number Diff line change
Expand Up @@ -212,6 +212,7 @@ def merge(
if merge_filter:
on = exp.and_(merge_filter, on)

match_expressions = []
if not when_matched:
match_condition = None
unique_key_names = [y.name for y in unique_key]
Expand All @@ -230,23 +231,24 @@ def merge(
)
)

match_expressions = [
exp.When(
matched=True,
source=False,
condition=match_condition,
then=exp.Update(
expressions=[
exp.column(col, MERGE_TARGET_ALIAS).eq(
exp.column(col, MERGE_SOURCE_ALIAS)
)
for col in columns_to_types_no_keys
],
),
if target_columns_no_keys:
match_expressions.append(
exp.When(
matched=True,
source=False,
condition=match_condition,
then=exp.Update(
expressions=[
exp.column(col, MERGE_TARGET_ALIAS).eq(
exp.column(col, MERGE_SOURCE_ALIAS)
)
for col in columns_to_types_no_keys
],
),
)
)
]
else:
match_expressions = when_matched.copy().expressions
match_expressions.extend(when_matched.copy().expressions)

match_expressions.append(
exp.When(
Expand Down
26 changes: 26 additions & 0 deletions tests/core/engine_adapter/test_mssql.py
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Original file line number Diff line number Diff line change
Expand Up @@ -456,6 +456,8 @@ def test_merge_pandas(
temp_table_mock.return_value = make_temp_table_name(table_name, temp_table_id)

df = pd.DataFrame({"id": [1, 2, 3], "ts": [1, 2, 3], "val": [4, 5, 6]})

# 1 key
adapter.merge(
target_table=table_name,
source_table=df,
Expand All @@ -476,6 +478,7 @@ def test_merge_pandas(
f"DROP TABLE IF EXISTS [__temp_target_{temp_table_id}];",
]

# 2 keys
adapter.cursor.reset_mock()
adapter._connection_pool.get().reset_mock()
temp_table_mock.return_value = make_temp_table_name(table_name, temp_table_id)
Expand All @@ -499,6 +502,29 @@ def test_merge_pandas(
f"DROP TABLE IF EXISTS [__temp_target_{temp_table_id}];",
]

# all model columns are keys
adapter.cursor.reset_mock()
adapter._connection_pool.get().reset_mock()
temp_table_mock.return_value = make_temp_table_name(table_name, temp_table_id)
adapter.merge(
target_table=table_name,
source_table=df,
columns_to_types={
"id": exp.DataType.build("int"),
"ts": exp.DataType.build("TIMESTAMP"),
},
unique_key=[exp.to_identifier("id"), exp.to_column("ts")],
)
adapter._connection_pool.get().bulk_copy.assert_called_with(
f"__temp_target_{temp_table_id}", [(1, 1), (2, 2), (3, 3)]
)

assert to_sql_calls(adapter) == [
f"""IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = '__temp_target_{temp_table_id}') EXEC('CREATE TABLE [__temp_target_{temp_table_id}] ([id] INTEGER, [ts] DATETIME2)');""",
f"MERGE INTO [target] AS [__MERGE_TARGET__] USING (SELECT CAST([id] AS INTEGER) AS [id], CAST([ts] AS DATETIME2) AS [ts] FROM [__temp_target_{temp_table_id}]) AS [__MERGE_SOURCE__] ON [__MERGE_TARGET__].[id] = [__MERGE_SOURCE__].[id] AND [__MERGE_TARGET__].[ts] = [__MERGE_SOURCE__].[ts] WHEN NOT MATCHED THEN INSERT ([id], [ts]) VALUES ([__MERGE_SOURCE__].[id], [__MERGE_SOURCE__].[ts]);",
f"DROP TABLE IF EXISTS [__temp_target_{temp_table_id}];",
]


def test_replace_query(make_mocked_engine_adapter: t.Callable):
adapter = make_mocked_engine_adapter(MSSQLEngineAdapter)
Expand Down