预演

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

@@ -22,6 +22,7 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
     public DbSet<Student> Students => Set<Student>();
     public DbSet<CourseCategory> CourseCategories => Set<CourseCategory>();
     public DbSet<Course> Courses => Set<Course>();
+    public DbSet<CoursePrerequisite> CoursePrerequisites => Set<CoursePrerequisite>();
     public DbSet<CurriculumPlan> CurriculumPlans => Set<CurriculumPlan>();
     public DbSet<CurriculumModule> CurriculumModules => Set<CurriculumModule>();
     public DbSet<CurriculumCourse> CurriculumCourses => Set<CurriculumCourse>();
@@ -247,6 +248,20 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
                 .OnDelete(DeleteBehavior.Restrict);
         });
 
+        builder.Entity<CoursePrerequisite>(entity =>
+        {
+            entity.HasIndex(x => new { x.CourseId, x.PrerequisiteCourseId })
+                .IsUnique();
+            entity.HasOne(x => x.Course)
+                .WithMany(x => x.Prerequisites)
+                .HasForeignKey(x => x.CourseId)
+                .OnDelete(DeleteBehavior.Cascade);
+            entity.HasOne(x => x.PrerequisiteCourse)
+                .WithMany(x => x.RequiredByCourses)
+                .HasForeignKey(x => x.PrerequisiteCourseId)
+                .OnDelete(DeleteBehavior.Restrict);
+        });
+
         builder.Entity<CurriculumPlan>(entity =>
         {
             entity.Property(x => x.Name).HasMaxLength(120);

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

@@ -62,6 +62,8 @@ public sealed class DevelopmentSqliteMigrator(
         "20260726_33_background_job_outbox";
     private const string CourseAdjustmentOccurrencesMigration =
         "20260727_34_course_adjustment_occurrences";
+    private const string AcademicPlanningPrerequisitesMigration =
+        "20260727_35_academic_planning_prerequisites";
 
     public async Task MigrateAsync(CancellationToken cancellationToken = default)
     {
@@ -453,6 +455,19 @@ public sealed class DevelopmentSqliteMigrator(
             BackgroundJobOutboxMigration,
             backgroundJobOutboxExists ? [] : BackgroundJobOutboxStatements,
             cancellationToken);
+
+        var coursePrerequisitesExist = await db.Database
+            .SqlQueryRaw<int>(
+                """
+                SELECT COUNT(*) AS "Value"
+                FROM sqlite_master
+                WHERE type = 'table' AND name = 'CoursePrerequisites'
+                """)
+            .AnyAsync(value => value > 0, cancellationToken);
+        await ApplyMigrationAsync(
+            AcademicPlanningPrerequisitesMigration,
+            coursePrerequisitesExist ? [] : AcademicPlanningPrerequisiteStatements,
+            cancellationToken);
     }
 
     private async Task ApplyMigrationAsync(
@@ -2090,4 +2105,31 @@ public sealed class DevelopmentSqliteMigrator(
         ON "BackgroundJobOutboxMessages" ("State", "CompletedAt");
         """
     ];
+
+    private static readonly string[] AcademicPlanningPrerequisiteStatements =
+    [
+        """
+        CREATE TABLE "CoursePrerequisites" (
+            "Id" TEXT NOT NULL CONSTRAINT "PK_CoursePrerequisites" PRIMARY KEY,
+            "CourseId" TEXT NOT NULL,
+            "PrerequisiteCourseId" TEXT NOT NULL,
+            "CreatedAt" TEXT NOT NULL,
+            "UpdatedAt" TEXT NOT NULL,
+            CONSTRAINT "FK_CoursePrerequisites_Courses_CourseId"
+                FOREIGN KEY ("CourseId") REFERENCES "Courses" ("Id")
+                ON DELETE CASCADE,
+            CONSTRAINT "FK_CoursePrerequisites_Courses_PrerequisiteCourseId"
+                FOREIGN KEY ("PrerequisiteCourseId") REFERENCES "Courses" ("Id")
+                ON DELETE RESTRICT
+        );
+        """,
+        """
+        CREATE UNIQUE INDEX "IX_CoursePrerequisites_CourseId_PrerequisiteCourseId"
+        ON "CoursePrerequisites" ("CourseId", "PrerequisiteCourseId");
+        """,
+        """
+        CREATE INDEX "IX_CoursePrerequisites_PrerequisiteCourseId"
+        ON "CoursePrerequisites" ("PrerequisiteCourseId");
+        """
+    ];
 }

src/Jiaowu.Api/Infrastructure/Persistence/Migrations/MySql/20260727034343_AcademicPlanningPrerequisites.cs

@@ -0,0 +1,61 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
+{
+    /// <inheritdoc />
+    public partial class AcademicPlanningPrerequisites : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "CoursePrerequisites",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "char(36)", nullable: false),
+                    CourseId = table.Column<Guid>(type: "char(36)", nullable: false),
+                    PrerequisiteCourseId = table.Column<Guid>(type: "char(36)", nullable: false),
+                    CreatedAt = table.Column<DateTime>(type: "datetime(6)", nullable: false),
+                    UpdatedAt = table.Column<DateTime>(type: "datetime(6)", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_CoursePrerequisites", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_CoursePrerequisites_Courses_CourseId",
+                        column: x => x.CourseId,
+                        principalTable: "Courses",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "FK_CoursePrerequisites_Courses_PrerequisiteCourseId",
+                        column: x => x.PrerequisiteCourseId,
+                        principalTable: "Courses",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Restrict);
+                })
+                .Annotation("MySQL:Charset", "utf8mb4");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_CoursePrerequisites_CourseId_PrerequisiteCourseId",
+                table: "CoursePrerequisites",
+                columns: new[] { "CourseId", "PrerequisiteCourseId" },
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_CoursePrerequisites_PrerequisiteCourseId",
+                table: "CoursePrerequisites",
+                column: "PrerequisiteCourseId");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "CoursePrerequisites");
+        }
+    }
+}

src/Jiaowu.Api/Infrastructure/Persistence/Migrations/MySql/AppDbContextModelSnapshot.cs

@@ -908,6 +908,34 @@ namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
                     b.ToTable("CourseExemptions");
                 });
 
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.CoursePrerequisite", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("char(36)");
+
+                    b.Property<Guid>("CourseId")
+                        .HasColumnType("char(36)");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.Property<Guid>("PrerequisiteCourseId")
+                        .HasColumnType("char(36)");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("PrerequisiteCourseId");
+
+                    b.HasIndex("CourseId", "PrerequisiteCourseId")
+                        .IsUnique();
+
+                    b.ToTable("CoursePrerequisites");
+                });
+
             modelBuilder.Entity("Jiaowu.Api.Domain.Academic.CourseSelectionOffering", b =>
                 {
                     b.Property<Guid>("Id")
@@ -3818,6 +3846,25 @@ namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
                     b.Navigation("TeachingTask");
                 });
 
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.CoursePrerequisite", b =>
+                {
+                    b.HasOne("Jiaowu.Api.Domain.Academic.Course", "Course")
+                        .WithMany("Prerequisites")
+                        .HasForeignKey("CourseId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("Jiaowu.Api.Domain.Academic.Course", "PrerequisiteCourse")
+                        .WithMany("RequiredByCourses")
+                        .HasForeignKey("PrerequisiteCourseId")
+                        .OnDelete(DeleteBehavior.Restrict)
+                        .IsRequired();
+
+                    b.Navigation("Course");
+
+                    b.Navigation("PrerequisiteCourse");
+                });
+
             modelBuilder.Entity("Jiaowu.Api.Domain.Academic.CourseSelectionOffering", b =>
                 {
                     b.HasOne("Jiaowu.Api.Domain.Academic.CourseSelectionRound", "CourseSelectionRound")
@@ -4734,6 +4781,13 @@ namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
                     b.Navigation("Records");
                 });
 
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.Course", b =>
+                {
+                    b.Navigation("Prerequisites");
+
+                    b.Navigation("RequiredByCourses");
+                });
+
             modelBuilder.Entity("Jiaowu.Api.Domain.Academic.CourseSelectionOffering", b =>
                 {
                     b.Navigation("Enrollments");