ICodeFirst 增加 ConfigEntity 方法，现实干净实体无特性的需求

FreeSql/DataAnnotations/ColumnAttribute.cs

@@ -16,18 +16,19 @@ namespace FreeSql.DataAnnotations {
 		/// </summary>
 		public string DbType { get; set; }
 
+		internal bool? _IsPrimary, _IsIdentity, _IsNullable;
 		/// <summary>
 		/// 主键
 		/// </summary>
-		public bool IsPrimary { get; set; }
+		public bool IsPrimary { get => _IsPrimary ?? false; set => _IsPrimary = value; }
 		/// <summary>
 		/// 自增标识
 		/// </summary>
-		public bool IsIdentity { get; set; }
+		public bool IsIdentity { get => _IsIdentity ?? false; set => _IsIdentity = value; }
 		/// <summary>
 		/// 是否可DBNull
 		/// </summary>
-		public bool IsNullable { get; set; }
+		public bool IsNullable { get => _IsNullable ?? false; set => _IsNullable = value; }
 
 		/// <summary>
 		/// 数据库默认值

FreeSql/DataAnnotations/ColumnFluent.cs

@@ -0,0 +1,54 @@
+using System;
+
+namespace FreeSql.DataAnnotations {
+	public class ColumnFluent<T> {
+
+		public ColumnFluent(ColumnAttribute column) {
+			_column = column;
+		}
+
+		ColumnAttribute _column;
+		/// <summary>
+		/// 数据库列名
+		/// </summary>
+		public ColumnFluent<T> Name(string value) {
+			_column.Name = value;
+			return this;
+		}
+		/// <summary>
+		/// 指定数据库旧的列名，修改实体属性命名时，同时设置此参数为修改之前的值，CodeFirst才可以正确修改数据库字段；否则将视为【新增字段】
+		/// </summary>
+		public ColumnFluent<T> OldName(string value) {
+			_column.OldName = value;
+			return this;
+		}
+		/// <summary>
+		/// 数据库类型，如： varchar(255)
+		/// </summary>
+		public ColumnFluent<T> DbType(string value) {
+			_column.DbType = value;
+			return this;
+		}
+
+		/// <summary>
+		/// 主键
+		/// </summary>
+		public ColumnFluent<T> IsPrimary(bool value) {
+			_column.IsPrimary = value;
+			return this;
+		}
+		/// 自增标识
+		/// </summary>
+		public ColumnFluent<T> IsIdentity(bool value) {
+			_column.IsIdentity = value;
+			return this;
+		}
+		/// <summary>
+		/// 是否可DBNull
+		/// </summary>
+		public ColumnFluent<T> IsNullable(bool value) {
+			_column.IsNullable = value;
+			return this;
+		}
+	}
+}

FreeSql/DataAnnotations/TableAttribute.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Concurrent;
 
 namespace FreeSql.DataAnnotations {
 	public class TableAttribute : Attribute {
@@ -15,5 +16,7 @@ namespace FreeSql.DataAnnotations {
 		/// 查询过滤SQL，实现类似 a.IsDeleted = 1 功能
 		/// </summary>
 		public string SelectFilter { get; set; }
+
+		internal ConcurrentDictionary<string, ColumnAttribute> _columns = new ConcurrentDictionary<string, ColumnAttribute>(StringComparer.CurrentCultureIgnoreCase);
 	}
 }

FreeSql/DataAnnotations/TableFluent.cs

@@ -0,0 +1,43 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Concurrent;
+using System.Linq.Expressions;
+
+namespace FreeSql.DataAnnotations {
+	public class TableFluent<T> {
+
+		public TableFluent(TableAttribute table) {
+			_table = table;
+		}
+
+		TableAttribute _table;
+		/// <summary>
+		/// 数据库表名
+		/// </summary>
+		public TableFluent<T> Name(string value) {
+			_table.Name = value;
+			return this;
+		}
+		/// <summary>
+		/// 指定数据库旧的表名，修改实体命名时，同时设置此参数为修改之前的值，CodeFirst才可以正确修改数据库表；否则将视为【创建新表】
+		/// </summary>
+		public TableFluent<T> OldName(string value) {
+			_table.OldName = value;
+			return this;
+		}
+		/// <summary>
+		/// 查询过滤SQL，实现类似 a.IsDeleted = 1 功能
+		/// </summary>
+		public TableFluent<T> SelectFilter(string value) {
+			_table.SelectFilter = value;
+			return this;
+		}
+
+		public ColumnFluent<TProto> Property<TProto>(Expression<Func<T, TProto>> column) {
+			var proto = (column.Body as MemberExpression)?.Member;
+			if (proto == null) throw new FormatException($"错误的表达式格式 {column}");
+			var col = _table._columns.GetOrAdd(proto.Name, name => new ColumnAttribute { Name = proto.Name });
+			return new ColumnFluent<TProto>(col);
+		}
+	}
+}