1 files changed, 162 insertions, 0 deletions
diff --git a/alembic/operations/toimpl.py b/alembic/operations/toimpl.py
new file mode 100644
index 0000000..1327367
--- /dev/null
+++ b/alembic/operations/toimpl.py
@@ -0,0 +1,162 @@
+from . import ops
+
+from . import Operations
+from sqlalchemy import schema as sa_schema
+
+
+@Operations.implementation_for(ops.AlterColumnOp)
+def alter_column(operations, operation):
+
+    compiler = operations.impl.dialect.statement_compiler(
+        operations.impl.dialect,
+        None
+    )
+
+    existing_type = operation.existing_type
+    existing_nullable = operation.existing_nullable
+    existing_server_default = operation.existing_server_default
+    type_ = operation.modify_type
+    column_name = operation.column_name
+    table_name = operation.table_name
+    schema = operation.schema
+    server_default = operation.modify_server_default
+    new_column_name = operation.modify_name
+    nullable = operation.modify_nullable
+
+    def _count_constraint(constraint):
+        return not isinstance(
+            constraint,
+            sa_schema.PrimaryKeyConstraint) and \
+            (not constraint._create_rule or
+                constraint._create_rule(compiler))
+
+    if existing_type and type_:
+        t = operations.schema_obj.table(
+            table_name,
+            sa_schema.Column(column_name, existing_type),
+            schema=schema
+        )
+        for constraint in t.constraints:
+            if _count_constraint(constraint):
+                operations.impl.drop_constraint(constraint)
+
+    operations.impl.alter_column(
+        table_name, column_name,
+        nullable=nullable,
+        server_default=server_default,
+        name=new_column_name,
+        type_=type_,
+        schema=schema,
+        existing_type=existing_type,
+        existing_server_default=existing_server_default,
+        existing_nullable=existing_nullable,
+        **operation.kw
+    )
+
+    if type_:
+        t = operations.schema_obj.table(
+            table_name,
+            operations.schema_obj.column(column_name, type_),
+            schema=schema
+        )
+        for constraint in t.constraints:
+            if _count_constraint(constraint):
+                operations.impl.add_constraint(constraint)
+
+
+@Operations.implementation_for(ops.DropTableOp)
+def drop_table(operations, operation):
+    operations.impl.drop_table(
+        operation.to_table(operations.migration_context)
+    )
+
+
+@Operations.implementation_for(ops.DropColumnOp)
+def drop_column(operations, operation):
+    column = operation.to_column(operations.migration_context)
+    operations.impl.drop_column(
+        operation.table_name,
+        column,
+        schema=operation.schema,
+        **operation.kw
+    )
+
+
+@Operations.implementation_for(ops.CreateIndexOp)
+def create_index(operations, operation):
+    idx = operation.to_index(operations.migration_context)
+    operations.impl.create_index(idx)
+
+
+@Operations.implementation_for(ops.DropIndexOp)
+def drop_index(operations, operation):
+    operations.impl.drop_index(
+        operation.to_index(operations.migration_context)
+    )
+
+
+@Operations.implementation_for(ops.CreateTableOp)
+def create_table(operations, operation):
+    table = operation.to_table(operations.migration_context)
+    operations.impl.create_table(table)
+    return table
+
+
+@Operations.implementation_for(ops.RenameTableOp)
+def rename_table(operations, operation):
+    operations.impl.rename_table(
+        operation.table_name,
+        operation.new_table_name,
+        schema=operation.schema)
+
+
+@Operations.implementation_for(ops.AddColumnOp)
+def add_column(operations, operation):
+    table_name = operation.table_name
+    column = operation.column
+    schema = operation.schema
+
+    t = operations.schema_obj.table(table_name, column, schema=schema)
+    operations.impl.add_column(
+        table_name,
+        column,
+        schema=schema
+    )
+    for constraint in t.constraints:
+        if not isinstance(constraint, sa_schema.PrimaryKeyConstraint):
+            operations.impl.add_constraint(constraint)
+    for index in t.indexes:
+        operations.impl.create_index(index)
+
+
+@Operations.implementation_for(ops.AddConstraintOp)
+def create_constraint(operations, operation):
+    operations.impl.add_constraint(
+        operation.to_constraint(operations.migration_context)
+    )
+
+
+@Operations.implementation_for(ops.DropConstraintOp)
+def drop_constraint(operations, operation):
+    operations.impl.drop_constraint(
+        operations.schema_obj.generic_constraint(
+            operation.constraint_name,
+            operation.table_name,
+            operation.constraint_type,
+            schema=operation.schema,
+        )
+    )
+
+
+@Operations.implementation_for(ops.BulkInsertOp)
+def bulk_insert(operations, operation):
+    operations.impl.bulk_insert(
+        operation.table, operation.rows, multiinsert=operation.multiinsert)
+
+
+@Operations.implementation_for(ops.ExecuteSQLOp)
+def execute_sql(operations, operation):
+    operations.migration_context.impl.execute(
+        operation.sqltext,
+        execution_options=operation.execution_options
+    )