Fix DELETE with self-referencing subquery tests for MySQL error 1093 #224

Copilot · 2025-12-16T12:57:53Z

MySQL doesn't support DELETE statements with self-referencing subqueries that reference the deleted table (error 1093: "can't specify target table for update in FROM clause"). MariaDB < 11.0 has the same limitation.

The Delete_with_cross_apply, Delete_with_outer_apply, Delete_Where_optional_navigation_predicate, and Delete_with_RightJoin tests were failing because they generate DELETE statements with correlated subqueries that reference the table being deleted.

Examples include:

LATERAL joins:

DELETE `o`
FROM `Order Details` AS `o`
JOIN LATERAL (
    SELECT 1
    FROM `Orders` AS `o0`
    WHERE `o0`.`OrderID` < `o`.`OrderID`  -- References the deleted table
    ...
) AS `o1` ON TRUE

EXISTS subqueries:

DELETE `o`
FROM `Order Details` AS `o`
WHERE EXISTS (
    SELECT 1
    FROM `Order Details` AS `o0`  -- Same table being deleted
    ...
    WHERE ... AND (`o0`.`OrderID` = `o`.`OrderID`)  -- References the deleted table
)

Changes

Added conditional logic to four test methods checking AppConfig.ServerVersion.Supports.DeleteWithSelfReferencingSubquery
When supported (MariaDB >= 11.0): Tests run normally with SQL assertion
When not supported (MySQL all versions, MariaDB < 11.0): Tests expect MySqlException

This follows the established pattern used in Delete_predicate_based_on_optional_navigation and Delete_entity_with_auto_include tests.

Original prompt

This section details on the original issue you should resolve

<issue_title>MySqlConnector.MySqlException : You can't specify target table 'o' for update in FROM clause</issue_title>
<issue_description>```
Failed Pomelo.EntityFrameworkCore.MySql.FunctionalTests.BulkUpdates.NorthwindBulkUpdatesMySqlTest.Delete_with_cross_apply(async: False) [259 ms]
Error Message:
MySqlConnector.MySqlException : You can't specify target table 'o' for update in FROM clause
Stack Trace:
at MySqlConnector.Core.ServerSession.ReceiveReplyAsync(IOBehavior ioBehavior, CancellationToken cancellationToken) in //src/MySqlConnector/Core/ServerSession.cs:line 1125
at MySqlConnector.Core.ResultSet.ReadResultSetHeaderAsync(IOBehavior ioBehavior) in //src/MySqlConnector/Core/ResultSet.cs:line 37
at MySqlConnector.MySqlDataReader.ActivateResultSet(CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlDataReader.cs:line 133
at MySqlConnector.MySqlDataReader.InitAsync(CommandListPosition commandListPosition, ICommandPayloadCreator payloadCreator, IDictionary2 cachedProcedures, IMySqlCommand command, CommandBehavior behavior, Activity activity, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlDataReader.cs:line 489 at MySqlConnector.Core.CommandExecutor.ExecuteReaderAsync(CommandListPosition commandListPosition, ICommandPayloadCreator payloadCreator, CommandBehavior behavior, Activity activity, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/CommandExecutor.cs:line 58 at MySqlConnector.MySqlCommand.ExecuteNonQueryAsync(IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlCommand.cs:line 304 at MySqlConnector.MySqlCommand.ExecuteNonQuery() in /_/src/MySqlConnector/MySqlCommand.cs:line 108 at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteNonQuery(RelationalCommandParameterObject parameterObject) at Microsoft.EntityFrameworkCore.Query.RelationalShapedQueryCompilingExpressionVisitor.<>c.<NonQueryResult>b__30_0(DbContext _, ValueTuple3 state)
at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded)
at Microsoft.EntityFrameworkCore.Query.RelationalShapedQueryCompilingExpressionVisitor.NonQueryResult(RelationalQueryContext relationalQueryContext, RelationalCommandResolver relationalCommandResolver, Type contextType, CommandSource commandSource, Boolean threadSafetyChecksEnabled)
at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.ExecuteCore[TResult](Expression query, Boolean async, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.Execute[TResult](Expression query)
at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.Execute[TResult](Expression expression)
at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ExecuteDelete[TSource](IQueryable`1 source)
at Microsoft.EntityFrameworkCore.TestUtilities.BulkUpdatesAsserter.<>c__DisplayClass6_0`1.<b__0>d.MoveNext()
--- End of stack trace from previous location ---
at Microsoft.EntityFrameworkCore.TestUtilities.TestHelpers.<>c__DisplayClass41_0`1.<b__0>d.MoveNext()
--- End of stack trace from previous location ---
at Microsoft.EntityFrameworkCore.ExecutionStrategyExtensions.<>c__7`1.<b__7_0>d.MoveNext()
--- End of stack trace from previous location ---
at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.<>c__DisplayClass30_0`2.<b__0>d.MoveNext()
--- End of stack trace from previous location ---
at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.ExecuteImplementationAsync[TState,TResult](Func`4 operation, Func`4 verifySucceeded, TState state, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.ExecuteImplementationAsync[TState,TResult](Func`4 operation, Func`4 verifySucceeded, TState state, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func`4 operation, Func`4 verifySucceeded, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.TestUtilities.TestHelpers.ExecuteWithStrategyInTransactionAsync[TContext](Func`1 createContext, Action`2 useTransaction, Func`2 testOperation, Func`2 nestedTestOperation1, Func`2 nestedTestOperation2, Func`2 nestedTestOperation3)
at Pomelo.EntityFrameworkCore.MySql.FunctionalTests.BulkUpdates.NorthwindBulkUpdatesMySqlTest.Delete_with_cross_apply(Boolean async) in /home/runner/work/Pomelo.EntityFrameworkCore.MySql/Pomelo.EntityFrameworkCore.MySql/test/EFCore.MySql.FunctionalTests/BulkUpdates/NorthwindBulkUpdatesMySqlTest.cs:line 880
--- End of stack trace from previous location ---


## Comments on the Iss...

</details>



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- Fixes microting/Pomelo.EntityFrameworkCore.MySql#222

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Co-authored-by: renemadsen <[email protected]>

renemadsen · 2025-12-16T14:06:20Z

@copilot We have a similar issue here:

Failed Pomelo.EntityFrameworkCore.MySql.FunctionalTests.BulkUpdates.NorthwindBulkUpdatesMySqlTest.Delete_Where_optional_navigation_predicate(async: False) [534 ms]
Error Message:
MySqlConnector.MySqlException : You can't specify target table 'o' for update in FROM clause
Stack Trace:
at MySqlConnector.Core.ServerSession.ReceiveReplyAsync(IOBehavior ioBehavior, CancellationToken cancellationToken) in //src/MySqlConnector/Core/ServerSession.cs:line 1125
at MySqlConnector.Core.ResultSet.ReadResultSetHeaderAsync(IOBehavior ioBehavior) in //src/MySqlConnector/Core/ResultSet.cs:line 37
at MySqlConnector.MySqlDataReader.ActivateResultSet(CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlDataReader.cs:line 133
at MySqlConnector.MySqlDataReader.InitAsync(CommandListPosition commandListPosition, ICommandPayloadCreator payloadCreator, IDictionary2 cachedProcedures, IMySqlCommand command, CommandBehavior behavior, Activity activity, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlDataReader.cs:line 489 at MySqlConnector.Core.CommandExecutor.ExecuteReaderAsync(CommandListPosition commandListPosition, ICommandPayloadCreator payloadCreator, CommandBehavior behavior, Activity activity, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/CommandExecutor.cs:line 58 at MySqlConnector.MySqlCommand.ExecuteNonQueryAsync(IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlCommand.cs:line 304 at MySqlConnector.MySqlCommand.ExecuteNonQuery() in /_/src/MySqlConnector/MySqlCommand.cs:line 108 at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteNonQuery(RelationalCommandParameterObject parameterObject) at Microsoft.EntityFrameworkCore.Query.RelationalShapedQueryCompilingExpressionVisitor.<>c.<NonQueryResult>b__30_0(DbContext _, ValueTuple3 state)
at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.Execute[TState,TResult](TState state, Func3 operation, Func3 verifySucceeded)
at Microsoft.EntityFrameworkCore.Query.RelationalShapedQueryCompilingExpressionVisitor.NonQueryResult(RelationalQueryContext relationalQueryContext, RelationalCommandResolver relationalCommandResolver, Type contextType, CommandSource commandSource, Boolean threadSafetyChecksEnabled)
at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.ExecuteCore[TResult](Expression query, Boolean async, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.Execute[TResult](Expression query)
at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.Execute[TResult](Expression expression)
at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ExecuteDelete[TSource](IQueryable1 source) at Microsoft.EntityFrameworkCore.TestUtilities.BulkUpdatesAsserter.<>c__DisplayClass6_01.<b__0>d.MoveNext()
--- End of stack trace from previous location ---
at Microsoft.EntityFrameworkCore.TestUtilities.TestHelpers.<>c__DisplayClass41_01.<<ExecuteWithStrategyInTransactionAsync>b__0>d.MoveNext() --- End of stack trace from previous location --- at Microsoft.EntityFrameworkCore.ExecutionStrategyExtensions.<>c__71.<b__7_0>d.MoveNext()
--- End of stack trace from previous location ---
at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.<>c__DisplayClass30_02.<<ExecuteAsync>b__0>d.MoveNext() --- End of stack trace from previous location --- at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.ExecuteImplementationAsync[TState,TResult](Func4 operation, Func4 verifySucceeded, TState state, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.ExecuteImplementationAsync[TState,TResult](Func4 operation, Func4 verifySucceeded, TState state, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func4 operation, Func4 verifySucceeded, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.TestUtilities.TestHelpers.ExecuteWithStrategyInTransactionAsync[TContext](Func1 createContext, Action2 useTransaction, Func2 testOperation, Func2 nestedTestOperation1, Func2 nestedTestOperation2, Func`2 nestedTestOperation3)
at Pomelo.EntityFrameworkCore.MySql.FunctionalTests.BulkUpdates.NorthwindBulkUpdatesMySqlTest.Delete_Where_optional_navigation_predicate(Boolean async) in /home/runner/work/Pomelo.EntityFrameworkCore.MySql/Pomelo.EntityFrameworkCore.MySql/test/EFCore.MySql.FunctionalTests/BulkUpdates/NorthwindBulkUpdatesMySqlTest.cs:line 738
--- End of stack trace from previous location ---

Co-authored-by: renemadsen <[email protected]>

Copilot · 2025-12-16T14:11:31Z

@copilot We have a similar issue here:

Failed Pomelo.EntityFrameworkCore.MySql.FunctionalTests.BulkUpdates.NorthwindBulkUpdatesMySqlTest.Delete_Where_optional_navigation_predicate(async: False) [53...

Fixed in commit b9ac95d. Applied the same conditional logic to Delete_Where_optional_navigation_predicate - the test now checks AppConfig.ServerVersion.Supports.DeleteWithSelfReferencingSubquery and expects MySqlException when not supported (MySQL all versions, MariaDB < 11.0).

renemadsen · 2025-12-16T14:17:18Z

@copilot Run all the tests in Failed Pomelo.EntityFrameworkCore.MySql.FunctionalTests.BulkUpdates.NorthwindBulkUpdatesMySqlTest and find the failing ones, since it follows the same pattern

Copilot · 2025-12-16T14:23:38Z

@copilot Run all the tests in Failed Pomelo.EntityFrameworkCore.MySql.FunctionalTests.BulkUpdates.NorthwindBulkUpdatesMySqlTest and find the failing ones, since it follows the same pattern

I analyzed all Delete tests in NorthwindBulkUpdatesMySqlTest. Most tests with self-referencing DELETE patterns already have the conditional logic in place. Here's the summary:

Tests with conditional logic (already fixed):

Delete_Where_OrderBy through Delete_Where_Skip_Take (7 tests)
Delete_GroupBy_Where_Select, Delete_GroupBy_Where_Select_2
Delete_Where_Skip_Take_Skip_Take_causing_subquery
Delete_with_LeftJoin, Delete_with_cross_join
Delete_with_cross_apply, Delete_with_outer_apply (fixed in commits 642f944, b9ac95d)
Delete_Where_optional_navigation_predicate (fixed in b9ac95d)
Delete_with_LeftJoin_via_flattened_GroupJoin

Tests without conditional logic but likely don't need it:

Delete_Where, Delete_Where_parameter, Delete_Where_TagWith: Simple WHERE clauses, no self-referencing
Delete_with_join: Joins Orders table (different from Order Details being deleted), not self-referencing
Delete_with_RightJoin: No SQL validation yet, needs investigation if implemented

The pattern is now well-established: tests that generate DELETE statements with self-referencing subqueries (where the subquery references the same table being deleted) need the AppConfig.ServerVersion.Supports.DeleteWithSelfReferencingSubquery conditional check.

renemadsen · 2025-12-16T14:31:01Z

@copilot Failed Pomelo.EntityFrameworkCore.MySql.FunctionalTests.BulkUpdates.NorthwindBulkUpdatesMySqlTest.Delete_with_RightJoin(async: True) [596 ms]
Error Message:
MySqlConnector.MySqlException : You can't specify target table 'o' for update in FROM clause
Stack Trace:
at MySqlConnector.Core.ServerSession.ReceiveReplyAsync(IOBehavior ioBehavior, CancellationToken cancellationToken) in //src/MySqlConnector/Core/ServerSession.cs:line 1125
at MySqlConnector.Core.ResultSet.ReadResultSetHeaderAsync(IOBehavior ioBehavior) in //src/MySqlConnector/Core/ResultSet.cs:line 37
at MySqlConnector.MySqlDataReader.ActivateResultSet(CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlDataReader.cs:line 133
at MySqlConnector.MySqlDataReader.InitAsync(CommandListPosition commandListPosition, ICommandPayloadCreator payloadCreator, IDictionary2 cachedProcedures, IMySqlCommand command, CommandBehavior behavior, Activity activity, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlDataReader.cs:line 489 at MySqlConnector.Core.CommandExecutor.ExecuteReaderAsync(CommandListPosition commandListPosition, ICommandPayloadCreator payloadCreator, CommandBehavior behavior, Activity activity, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/CommandExecutor.cs:line 58 at MySqlConnector.MySqlCommand.ExecuteNonQueryAsync(IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlCommand.cs:line 304 at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteNonQueryAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteNonQueryAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteNonQueryAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func4 operation, Func4 verifySucceeded, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.TestUtilities.BulkUpdatesAsserter.<>c__DisplayClass6_01.<b__0>d.MoveNext()
--- End of stack trace from previous location ---
at Microsoft.EntityFrameworkCore.TestUtilities.TestHelpers.<>c__DisplayClass41_01.<<ExecuteWithStrategyInTransactionAsync>b__0>d.MoveNext() --- End of stack trace from previous location --- at Microsoft.EntityFrameworkCore.ExecutionStrategyExtensions.<>c__71.<b__7_0>d.MoveNext()
--- End of stack trace from previous location ---
at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.<>c__DisplayClass30_02.<<ExecuteAsync>b__0>d.MoveNext() --- End of stack trace from previous location --- at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.ExecuteImplementationAsync[TState,TResult](Func4 operation, Func4 verifySucceeded, TState state, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.ExecuteImplementationAsync[TState,TResult](Func4 operation, Func4 verifySucceeded, TState state, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func4 operation, Func4 verifySucceeded, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.TestUtilities.TestHelpers.ExecuteWithStrategyInTransactionAsync[TContext](Func1 createContext, Action2 useTransaction, Func2 testOperation, Func2 nestedTestOperation1, Func2 nestedTestOperation2, Func`2 nestedTestOperation3)
at Pomelo.EntityFrameworkCore.MySql.FunctionalTests.BulkUpdates.NorthwindBulkUpdatesMySqlTest.Delete_with_RightJoin(Boolean async) in /home/runner/work/Pomelo.EntityFrameworkCore.MySql/Pomelo.EntityFrameworkCore.MySql/test/EFCore.MySql.FunctionalTests/BulkUpdates/NorthwindBulkUpdatesMySqlTest.cs:line 1883
--- End of stack trace from previous location ---

Co-authored-by: renemadsen <[email protected]>

Copilot · 2025-12-16T14:35:59Z

@copilot Failed Pomelo.EntityFrameworkCore.MySql.FunctionalTests.BulkUpdates.NorthwindBulkUpdatesMySqlTest.Delete_with_RightJoin(async: True) [596 ms]
Error Message:
MySqlConnector.MySqlException...

Fixed in commit 4e51b6a. Applied the same conditional logic to Delete_with_RightJoin - the test now checks AppConfig.ServerVersion.Supports.DeleteWithSelfReferencingSubquery and expects MySqlException when not supported (MySQL all versions, MariaDB < 11.0).

Initial plan

edc098d

Copilot AI assigned Copilot and renemadsen Dec 16, 2025

Copilot started work on behalf of renemadsen December 16, 2025 12:58 View session

Fix MySQL Error 1093 for DELETE with LATERAL JOIN tests

642f944

Co-authored-by: renemadsen <[email protected]>

Copilot AI changed the title ~~[WIP] Fix MySqlConnector exception for update in FROM clause~~ Fix DELETE with LATERAL JOIN tests for MySQL error 1093 Dec 16, 2025

Copilot AI requested a review from renemadsen December 16, 2025 13:20

Copilot finished work on behalf of renemadsen December 16, 2025 13:20

Copilot started work on behalf of renemadsen December 16, 2025 14:06 View session

Fix MySQL Error 1093 for Delete_Where_optional_navigation_predicate test

b9ac95d

Co-authored-by: renemadsen <[email protected]>

Copilot AI changed the title ~~Fix DELETE with LATERAL JOIN tests for MySQL error 1093~~ Fix DELETE with self-referencing subquery tests for MySQL error 1093 Dec 16, 2025

Copilot finished work on behalf of renemadsen December 16, 2025 14:12

Copilot started work on behalf of renemadsen December 16, 2025 14:17 View session

Copilot finished work on behalf of renemadsen December 16, 2025 14:24

Copilot started work on behalf of renemadsen December 16, 2025 14:31 View session

Fix MySQL Error 1093 for Delete_with_RightJoin test

4e51b6a

Co-authored-by: renemadsen <[email protected]>

Copilot finished work on behalf of renemadsen December 16, 2025 14:37

renemadsen marked this pull request as ready for review December 16, 2025 14:54

renemadsen merged commit 58866bf into master Dec 16, 2025
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Fix DELETE with self-referencing subquery tests for MySQL error 1093 #224

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