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Extensions/FreeSql.Extensions.EfCoreFluentApi/readme.md

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+这个 FreeSql 扩展包，实现与 EfCore FluentApi 95% 相似的使用习惯；
+
+## 以假乱真
+
+```csharp
+static void Test()
+{
+    ICodeFirst cf = null;
+    cf.Entity<Song>(eb =>
+    {
+        eb.ToTable("tb_song");
+        eb.Ignore(a => a.Field1);
+        eb.Property(a => a.Title).HashColumnType("varchar(50)").IsRequired();
+        eb.Property(a => a.Url).HasMaxLength(100);
+
+        eb.Property(a => a.RowVersion).IsRowVersion();
+        eb.Property(a => a.CreateTime).HasDefaultValueSql("getdate()");
+
+        eb.HasKey(a => a.Id);
+        eb.HasIndex(a => a.Title).IsUnique().HasName("idx_xxx11");
+
+        //一对多、多对一
+        eb.HasOne(a => a.Type).HasForeignKey(a => a.TypeId).WithMany(a => a.Songs);
+
+        //多对多
+        eb.HasMany(a => a.Tags).WithMany(a => a.Songs, typeof(Song_tag));
+    });
+}
+
+public class SongType
+{
+    public int Id { get; set; }
+    public string Name { get; set; }
+
+    public List<Song> Songs { get; set; }
+}
+
+public class Song
+{
+    public int Id { get; set; }
+    public string Title { get; set; }
+    public string Url { get; set; }
+    public DateTime CreateTime { get; set; }
+
+    public int TypeId { get; set; }
+    public SongType Type { get; set; }
+    public List<Tag> Tags { get; set; }
+
+    public int Field1 { get; set; }
+    public long RowVersion { get; set; }
+}
+public class Song_tag
+{
+    public int Song_id { get; set; }
+    public Song Song { get; set; }
+
+    public int Tag_id { get; set; }
+    public Tag Tag { get; set; }
+}
+
+public class Tag
+{
+    [Column(IsIdentity = true)]
+    public int Id { get; set; }
+
+    public string Name { get; set; }
+
+    public List<Song> Songs { get; set; }
+}
+```