Fixes for Oracle MERGE implementation (DM-21748)

The _Merge class has to inherit Executable so that Connection can
execute it, the order of base classes for _Merge is important. Call to
bindparam() in generated MERGE needs a `type_` argument to correctly
interpret parameter data using all registered type decorators.

python/lsst/daf/butler/registries/oracleRegistry.py

@@ -24,14 +24,15 @@
 from sqlalchemy import create_engine
 from sqlalchemy.ext import compiler
 from sqlalchemy.sql import ClauseElement, and_, bindparam, select
+from sqlalchemy.sql.expression import Executable
 
 from lsst.daf.butler.core.config import Config
 from lsst.daf.butler.core.registryConfig import RegistryConfig
 
 from .sqlRegistry import SqlRegistry, SqlRegistryConfig
 
 
-class _Merge(ClauseElement):
+class _Merge(Executable, ClauseElement):
     def __init__(self, table, onConflict):
         self.table = table
         self.onConflict = onConflict
@@ -48,7 +49,7 @@ def _merge(merge, compiler, **kw):
     pkColumns = [col.name for col in table.primary_key]
     nonPkColumns = [col for col in allColumns if col not in pkColumns]
 
-    selectColumns = [bindparam(col).label(col) for col in allColumns]
+    selectColumns = [bindparam(col.name, type_=col.type).label(col.name) for col in table.columns]
     selectClause = select(selectColumns)
 
     tableAlias = table.alias("t")

tests/test_sqlRegistry.py

@@ -28,6 +28,7 @@
 from sqlalchemy import Table, Column, Integer
 from sqlalchemy.schema import MetaData
 from sqlalchemy.exc import IntegrityError
+from sqlalchemy.sql.expression import Executable
 
 import lsst.sphgeom
 
@@ -728,6 +729,8 @@ def testInsertConflictSqlite(self):
         expect = 'INSERT INTO insert_conflict_test (pk, value, "uniqVal") VALUES (?, ?, ?)' \
                  ' ON CONFLICT (pk) DO NOTHING'
         clause = InsertOnConflict(table, onConflict="ignore")
+        self.assertIsInstance(clause, Executable)
+        self.assertTrue(clause.supports_execution)
         query = clause.compile(dialect=sqlite.dialect())
         self.assertEqual(str(query), expect)
 
@@ -751,6 +754,8 @@ def testInsertConflictPG(self):
         expect = 'INSERT INTO insert_conflict_test (pk, value, \"uniqVal\")' \
                  ' VALUES (%(pk)s, %(value)s, %(uniqVal)s) ON CONFLICT (pk) DO NOTHING'
         clause = PostgreSqlRegistry._makeInsertWithConflictImpl(table, onConflict="ignore")
+        self.assertIsInstance(clause, Executable)
+        self.assertTrue(clause.supports_execution)
         query = clause.compile(dialect=postgresql.dialect())
         self.assertEqual(str(query), expect)
 
@@ -777,6 +782,8 @@ def testInsertConflictOracle(self):
                  'ON (t.pk = d.pk)\n' \
                  'WHEN NOT MATCHED THEN INSERT (pk, value, "uniqVal") VALUES (d.pk, d.value, d."uniqVal")'
         clause = _Merge(table, onConflict="ignore")
+        self.assertIsInstance(clause, Executable)
+        self.assertTrue(clause.supports_execution)
         query = clause.compile(dialect=oracle.dialect())
         self.assertEqual(str(query), expect)
 
@@ -786,6 +793,8 @@ def testInsertConflictOracle(self):
                  'WHEN MATCHED THEN UPDATE SET t.value = d.value, t."uniqVal" = d."uniqVal"\n' \
                  'WHEN NOT MATCHED THEN INSERT (pk, value, "uniqVal") VALUES (d.pk, d.value, d."uniqVal")'
         clause = _Merge(table, onConflict="replace")
+        self.assertIsInstance(clause, Executable)
+        self.assertTrue(clause.supports_execution)
         query = clause.compile(dialect=oracle.dialect())
         self.assertEqual(str(query), expect)