修复Mysql

src/Jiaowu.Api/Controllers/CoursesExcelController.cs

@@ -122,32 +122,39 @@ public sealed class CoursesExcelController(
         if (rows.Count == 0)
             return ValidationProblem("Excel 中没有可导入的课程数据。");
 
-        var errors = new List<string>();
-        await using var transaction =
-            await db.Database.BeginTransactionAsync(cancellationToken);
-        try
-        {
-            var result = await ImportRowsAsync(rows, errors, cancellationToken);
-            if (errors.Count > 0)
+        return await db.ExecuteInRetriableTransactionAsync<
+            ActionResult<ExcelImportResult>>(
+            async transaction =>
             {
-                await transaction.RollbackAsync(cancellationToken);
-                return ImportValidationProblem(errors);
-            }
+                var errors = new List<string>();
+                try
+                {
+                    var result = await ImportRowsAsync(
+                        rows,
+                        errors,
+                        cancellationToken);
+                    if (errors.Count > 0)
+                    {
+                        await transaction.RollbackAsync(cancellationToken);
+                        return ImportValidationProblem(errors);
+                    }
 
-            await db.SaveChangesAsync(cancellationToken);
-            await transaction.CommitAsync(cancellationToken);
-            return Ok(result);
-        }
-        catch (DbUpdateException)
-        {
-            await transaction.RollbackAsync(cancellationToken);
-            return Conflict(new ProblemDetails
-            {
-                Title = "导入失败",
-                Detail = "存在重复课程编码或无效关联，未写入任何课程。",
-                Status = StatusCodes.Status409Conflict
-            });
-        }
+                    await db.SaveChangesAsync(cancellationToken);
+                    await transaction.CommitAsync(cancellationToken);
+                    return Ok(result);
+                }
+                catch (DbUpdateException)
+                {
+                    await transaction.RollbackAsync(cancellationToken);
+                    return Conflict(new ProblemDetails
+                    {
+                        Title = "导入失败",
+                        Detail = "存在重复课程编码或无效关联，未写入任何课程。",
+                        Status = StatusCodes.Status409Conflict
+                    });
+                }
+            },
+            cancellationToken);
     }
 
     private async Task<ExcelImportResult> ImportRowsAsync(