1818from __future__ import annotations
1919
2020from abc import ABC , abstractmethod
21+ from enum import Enum
2122from typing import Generic , TypeVar
2223
2324from fastapi import HTTPException , Request , status
@@ -38,26 +39,46 @@ def exception_handler(self, request: Request, exc: T):
3839 raise NotImplementedError
3940
4041
42+ class _DatabaseDialect (Enum ):
43+ SQLITE = "sqlite"
44+ MYSQL = "mysql"
45+ POSTGRES = "postgres"
46+
47+
4148class _UniqueConstraintErrorHandler (BaseErrorHandler [IntegrityError ]):
4249 """Exception raised when trying to insert a duplicate value in a unique column."""
4350
51+ unique_constraint_error_prefix_dict : dict [_DatabaseDialect , str ] = {
52+ _DatabaseDialect .SQLITE : "UNIQUE constraint failed" ,
53+ _DatabaseDialect .MYSQL : "Duplicate entry" ,
54+ _DatabaseDialect .POSTGRES : "violates unique constraint" ,
55+ }
56+
4457 def __init__ (self ):
4558 super ().__init__ (IntegrityError )
46- self .unique_constraint_error_messages = [
47- "UNIQUE constraint failed" , # SQLite
48- "Duplicate entry" , # MySQL
49- "violates unique constraint" , # PostgreSQL
50- ]
59+ self .dialect : _DatabaseDialect .value | None = None
5160
5261 def exception_handler (self , request : Request , exc : IntegrityError ):
5362 """Handle IntegrityError exception."""
54- exc_orig_str = str (exc .orig )
55- if any (error_msg in exc_orig_str for error_msg in self .unique_constraint_error_messages ):
63+ if self ._is_dialect_matched (exc ):
5664 raise HTTPException (
5765 status_code = status .HTTP_409_CONFLICT ,
58- detail = "Unique constraint violation" ,
66+ detail = {
67+ "reason" : "Unique constraint violation" ,
68+ "statement" : str (exc .statement ),
69+ "orig_error" : str (exc .orig ),
70+ },
5971 )
6072
73+ def _is_dialect_matched (self , exc : IntegrityError ) -> bool :
74+ """Check if the exception matches the unique constraint error message for any dialect."""
75+ exc_orig_str = str (exc .orig )
76+ for dialect , error_msg in self .unique_constraint_error_prefix_dict .items ():
77+ if error_msg in exc_orig_str :
78+ self .dialect = dialect
79+ return True
80+ return False
81+
6182
6283DatabaseErrorHandlers = [
6384 _UniqueConstraintErrorHandler (),
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