选课批次：时间窗口、退课截止、学分上限、开放/关闭。

教学班投放：容量、班级范围、全校开放。
学生选退课：容量、重复课程、学分上限、课表冲突校验。
教学班实时名单。
校级、学院级、学生角色分级操作。
SQLite 本地增量升级及演示数据。
MySQL 正式 EF Core 迁移。
Vue 已编译进 wwwroot，单服务运行无需 npm run dev。
学生端和管理端均完成桌面、手机响应式检查。

src/Jiaowu.Api/Infrastructure/Persistence/DevelopmentSqliteMigrator.cs

@@ -11,6 +11,7 @@ public sealed class DevelopmentSqliteMigrator(
     private const string TeachingTasksMigration = "20260724_03_teaching_tasks";
     private const string SchedulesMigration = "20260724_04_schedules";
     private const string ClassCounselorMigration = "20260724_05_class_counselor";
+    private const string CourseSelectionMigration = "20260724_06_course_selection";
 
     public async Task MigrateAsync(CancellationToken cancellationToken = default)
     {
@@ -58,6 +59,10 @@ public sealed class DevelopmentSqliteMigrator(
                 ? ClassCounselorStatements.Skip(1)
                 : ClassCounselorStatements,
             cancellationToken);
+        await ApplyMigrationAsync(
+            CourseSelectionMigration,
+            CourseSelectionStatements,
+            cancellationToken);
     }
 
     private async Task ApplyMigrationAsync(
@@ -426,4 +431,79 @@ public sealed class DevelopmentSqliteMigrator(
             ON "AdministrativeClasses" ("CounselorUserId");
         """
     ];
+
+    private static readonly string[] CourseSelectionStatements =
+    [
+        """
+        CREATE TABLE IF NOT EXISTS "CourseSelectionRounds" (
+            "Id" TEXT NOT NULL CONSTRAINT "PK_CourseSelectionRounds" PRIMARY KEY,
+            "AcademicTermId" TEXT NOT NULL,
+            "Name" TEXT NOT NULL,
+            "StartsAt" TEXT NOT NULL,
+            "EndsAt" TEXT NOT NULL,
+            "WithdrawalEndsAt" TEXT NOT NULL,
+            "MaxCredits" TEXT NOT NULL,
+            "Status" INTEGER NOT NULL,
+            "Notes" TEXT NULL,
+            "CreatedAt" TEXT NOT NULL,
+            "UpdatedAt" TEXT NOT NULL,
+            CONSTRAINT "FK_CourseSelectionRounds_AcademicTerms_AcademicTermId"
+                FOREIGN KEY ("AcademicTermId") REFERENCES "AcademicTerms" ("Id") ON DELETE RESTRICT
+        );
+        """,
+        """
+        CREATE INDEX IF NOT EXISTS "IX_CourseSelectionRounds_AcademicTermId_Status"
+            ON "CourseSelectionRounds" ("AcademicTermId", "Status");
+        """,
+        """
+        CREATE TABLE IF NOT EXISTS "CourseSelectionOfferings" (
+            "Id" TEXT NOT NULL CONSTRAINT "PK_CourseSelectionOfferings" PRIMARY KEY,
+            "CourseSelectionRoundId" TEXT NOT NULL,
+            "TeachingTaskId" TEXT NOT NULL,
+            "Capacity" INTEGER NOT NULL,
+            "IsOpenToAll" INTEGER NOT NULL,
+            "Notes" TEXT NULL,
+            "CreatedAt" TEXT NOT NULL,
+            "UpdatedAt" TEXT NOT NULL,
+            CONSTRAINT "FK_CourseSelectionOfferings_CourseSelectionRounds_CourseSelectionRoundId"
+                FOREIGN KEY ("CourseSelectionRoundId") REFERENCES "CourseSelectionRounds" ("Id")
+                ON DELETE CASCADE,
+            CONSTRAINT "FK_CourseSelectionOfferings_TeachingTasks_TeachingTaskId"
+                FOREIGN KEY ("TeachingTaskId") REFERENCES "TeachingTasks" ("Id") ON DELETE RESTRICT
+        );
+        """,
+        """
+        CREATE UNIQUE INDEX IF NOT EXISTS "IX_CourseSelectionOfferings_CourseSelectionRoundId_TeachingTaskId"
+            ON "CourseSelectionOfferings" ("CourseSelectionRoundId", "TeachingTaskId");
+        """,
+        """
+        CREATE INDEX IF NOT EXISTS "IX_CourseSelectionOfferings_TeachingTaskId"
+            ON "CourseSelectionOfferings" ("TeachingTaskId");
+        """,
+        """
+        CREATE TABLE IF NOT EXISTS "CourseEnrollments" (
+            "Id" TEXT NOT NULL CONSTRAINT "PK_CourseEnrollments" PRIMARY KEY,
+            "CourseSelectionOfferingId" TEXT NOT NULL,
+            "StudentId" TEXT NOT NULL,
+            "Status" INTEGER NOT NULL,
+            "EnrolledAt" TEXT NOT NULL,
+            "WithdrawnAt" TEXT NULL,
+            "CreatedAt" TEXT NOT NULL,
+            "UpdatedAt" TEXT NOT NULL,
+            CONSTRAINT "FK_CourseEnrollments_CourseSelectionOfferings_CourseSelectionOfferingId"
+                FOREIGN KEY ("CourseSelectionOfferingId") REFERENCES "CourseSelectionOfferings" ("Id")
+                ON DELETE CASCADE,
+            CONSTRAINT "FK_CourseEnrollments_Students_StudentId"
+                FOREIGN KEY ("StudentId") REFERENCES "Students" ("Id") ON DELETE RESTRICT
+        );
+        """,
+        """
+        CREATE UNIQUE INDEX IF NOT EXISTS "IX_CourseEnrollments_CourseSelectionOfferingId_StudentId"
+            ON "CourseEnrollments" ("CourseSelectionOfferingId", "StudentId");
+        """,
+        """
+        CREATE INDEX IF NOT EXISTS "IX_CourseEnrollments_StudentId_Status"
+            ON "CourseEnrollments" ("StudentId", "Status");
+        """
+    ];
 }