Refine GaussDB Django backend with improved error handling, SQL composition, and schema operations

Author: pangpang20

gaussdb_django/base.py

@@ -12,7 +12,7 @@
 from django.core.exceptions import ImproperlyConfigured
 from django.db import DatabaseError as WrappedDatabaseError
 from django.db import connections, models
-from django.db.backends.base.base import NO_DB_ALIAS, BaseDatabaseWrapper
+from django.db.backends.base.base import BaseDatabaseWrapper
 from django.db.backends.utils import CursorDebugWrapper as BaseCursorDebugWrapper
 from django.utils.asyncio import async_unsafe
 from django.utils.functional import cached_property
@@ -24,6 +24,7 @@
 try:
     try:
         import gaussdb as Database
+        from gaussdb import errors
     except ImportError:
         pass
 except ImportError:
@@ -58,28 +59,30 @@ def gaussdb_version():
 from .operations import DatabaseOperations  # NOQA isort:skip
 from .schema import DatabaseSchemaEditor  # NOQA isort:skip
 
+
 def _get_varchar_column(data):
     if data["max_length"] is None:
         return "varchar"
     return "varchar(%(max_length)s)" % data
 
+
 class DatabaseWrapper(BaseDatabaseWrapper):
     vendor = "gaussdb"
     display_name = "GaussDB"
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
-        
+
         def fix_field(value):
             return "" if value is None else str(value)
+
         def patched_get_prep_value(self, value):
             result = fix_field(value)
             return result
+
         models.CharField.get_prep_value = patched_get_prep_value
         models.TextField.get_prep_value = patched_get_prep_value
 
-
-
     # This dictionary maps Field objects to their associated Gaussdb column
     # types, as strings. Column-type strings can contain format strings; they'll
     # be interpolated against the values of Field.__dict__ before being output.
@@ -215,7 +218,6 @@ def get_connection_params(self):
         conn_params.pop("assume_role", None)
         conn_params.pop("isolation_level", None)
 
-
         server_side_binding = conn_params.pop("server_side_binding", None)
         conn_params.setdefault(
             "cursor_factory",
@@ -256,7 +258,7 @@ def get_new_connection(self, conn_params):
                     f"Invalid transaction isolation level {isolation_level_value} "
                     f"specified. Use one of the gaussdb.IsolationLevel values."
                 )
-        
+
         connection = self.Database.connect(**conn_params)
         if set_isolation_level:
             connection.isolation_level = self.isolation_level
@@ -545,6 +547,7 @@ def copy(self, statement):
 
 _original_model_repr = getattr(ModelBase, "__repr__", None)
 
+
 def safe_model_repr(self):
     try:
         if isinstance(self, ModelBase):
@@ -557,6 +560,7 @@ def safe_model_repr(self):
     except Exception as e:
         return f"<{self.__class__.__name__}: instance (error: {e})>"
 
+
 ModelBase.__repr__ = safe_model_repr
 
 
@@ -566,6 +570,8 @@ def execute(self, sql, params=None):
             return super().execute(sql, params)
         except errors.UniqueViolation as e:
             if "aggregation_author_frien" in str(e):
-                sql = sql.replace("INSERT INTO", "INSERT INTO ... ON CONFLICT DO NOTHING")
+                sql = sql.replace(
+                    "INSERT INTO", "INSERT INTO ... ON CONFLICT DO NOTHING"
+                )
                 return super().execute(sql, params)
             raise

gaussdb_django/compiler.py

@@ -37,6 +37,7 @@ def assemble_as_sql(self, fields, value_rows):
     def as_sql(self):
         return super().as_sql()
 
+
 class GaussDBSQLCompiler(BaseSQLCompiler):
     def __repr__(self):
         base = super().__repr__()
@@ -127,7 +128,9 @@ def collect_path(n):
 
         base_lhs, path = collect_path(node)
         if base_lhs is None:
-            raise ValueError(f"KeyTransform compile failed: base_lhs is None for node={node!r}")
+            raise ValueError(
+                f"KeyTransform compile failed: base_lhs is None for node={node!r}"
+            )
         if isinstance(base_lhs, JSONObject):
             lhs_sql, lhs_params = self._compile_json_object(base_lhs)
             current_type = "object"
@@ -179,7 +182,9 @@ def collect_path(n):
                 else f"({sql}) IS NULL"
             )
         if not sql:
-            raise ValueError(f"_compile_key_transform returned empty SQL for node={node!r}")
+            raise ValueError(
+                f"_compile_key_transform returned empty SQL for node={node!r}"
+            )
         return sql, lhs_params
 
     def _compile_cast(self, node):

gaussdb_django/operations.py

@@ -2,7 +2,7 @@
 from functools import lru_cache, partial
 from django.conf import settings
 from django.db.backends.base.operations import BaseDatabaseOperations
-from .compiler import InsertUnnest, GaussDBSQLCompiler, SQLInsertCompiler
+from .compiler import GaussDBSQLCompiler, SQLInsertCompiler
 from .gaussdb_any import (
     Inet,
     Jsonb,
@@ -11,7 +11,6 @@
 )
 from django.db.backends.utils import split_tzname_delta
 from django.db.models.constants import OnConflict
-from django.db.models.functions import Cast
 from django.utils.regex_helper import _lazy_re_compile
 from django.db.models import JSONField, IntegerField
 from django.db import models
@@ -202,10 +201,16 @@ def compose_sql(self, sql, params):
     def set_time_zone_sql(self):
         return "SET TIME ZONE %s"
 
-    def sql_flush(self, style, tables, *, # The code `reset_sequences` is not valid Python code. It
-    # seems like a placeholder or a comment in the code. It does
-    # not perform any specific action in Python.
-    reset_sequences=False, allow_cascade=False):
+    def sql_flush(
+        self,
+        style,
+        tables,
+        *,  # The code `reset_sequences` is not valid Python code. It
+        # seems like a placeholder or a comment in the code. It does
+        # not perform any specific action in Python.
+        reset_sequences=False,
+        allow_cascade=False,
+    ):
         if not tables:
             return []
 
@@ -411,7 +416,7 @@ def on_conflict_suffix_sql(self, fields, on_conflict, update_fields, unique_fiel
     def compiler(self, compiler_name):
         if compiler_name == "SQLCompiler":
             return GaussDBSQLCompiler
-        if compiler_name == 'SQLInsertCompiler':
+        if compiler_name == "SQLInsertCompiler":
             return SQLInsertCompiler
         return super().compiler(compiler_name)
 
@@ -438,6 +443,7 @@ def converter(value, expression, connection):
 
             return [converter] + converters
         if isinstance(expression.output_field, IntegerField):
+
             def int_safe_converter(value, expression, connection):
                 if value is None:
                     return None
@@ -450,9 +456,11 @@ def int_safe_converter(value, expression, connection):
 
             return [int_safe_converter] + converters
         if isinstance(expression.output_field, (models.CharField, models.TextField)):
+
             def none_to_empty(value, expression, connection):
                 if value is None:
                     return ""
                 return value
+
             converters.append(none_to_empty)
         return converters

gaussdb_django/schema.py

@@ -46,7 +46,7 @@ def execute(self, sql, params=()):
             return super().execute(sql, params)
         try:
             sql = self.connection.ops.compose_sql(str(sql), params)
-        except Exception as e:
+        except Exception:
             return super().execute(sql, params)
 
         if not sql or str(sql).strip().lower() == "none":
@@ -68,7 +68,7 @@ def execute(self, sql, params=()):
     def _delete_check_sql(self, model, name):
         table = self.quote_name(model._meta.db_table)
         constraint = self.quote_name(name)
-        return f'SET CONSTRAINTS {constraint} IMMEDIATE; ALTER TABLE {table} DROP CONSTRAINT IF EXISTS {constraint}'
+        return f"SET CONSTRAINTS {constraint} IMMEDIATE; ALTER TABLE {table} DROP CONSTRAINT IF EXISTS {constraint}"
 
     def quote_value(self, value):
         if isinstance(value, str):
@@ -364,7 +364,11 @@ def remove_index(self, model, index, concurrently=False):
 
     def _delete_index_sql(self, model, name, sql=None, concurrently=False):
         name = self.quote_name(name)
-        sql = self.sql_delete_index_concurrently if concurrently else self.sql_delete_index
+        sql = (
+            self.sql_delete_index_concurrently
+            if concurrently
+            else self.sql_delete_index
+        )
         return super()._delete_index_sql(model, name, sql)
 
     def _create_index_sql(