CodeFirst（反射+特性）

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using System.Text;
 using Dapper;
 using System.Text.RegularExpressions;
 using System.Data.SqlClient;
 using System.ComponentModel;

 namespace CodeFirst
 {
     class Program
     {
         static readonly string SchemaName;
         static readonly string ConnectionString;

         static Program()
         {
             SchemaName = "22TopWeb";
             if (string.IsNullOrWhiteSpace(SchemaName))
             {
                 throw new Exception("'SchemaName' load failed");
             }
             if (new[] { "master", "model", "msdb", "tempdb" }.Contains(SchemaName))
             {
                 throw new Exception("'SchemaName' illegal");
             }
             ConnectionString = "Data Source=192.168.8.119;User ID=EQCCD_HUNTER;Password=zhey1bu2012;Initial Catalog=master;Pooling=true";
             if (string.IsNullOrWhiteSpace(ConnectionString))
             {
                 throw new Exception("'ConnectionString' load failed");
             }
             var pattern = @"Initial\s*Catalog\s*=\s*master";
             Match match = Regex.Match(ConnectionString, pattern, RegexOptions.IgnoreCase);
             if (match.Groups.Count > )
             {
                 //可能需要创建数据库
                 CheckSchema(ConnectionString, SchemaName);
                 ConnectionString = ConnectionString.Replace(match.Groups[].Value, "Initial Catalog=" + SchemaName);
             }
         }

         static void Main(string[] args)
         {
             var sql = GetTableCreateSql("CodeFirst.TB_Enterprise");

             ExcuteSql(ConnectionString, sql.Replace("GO", "")); //GO只能在查询分析器里使用

             Console.ReadKey();
         }

         /// <summary>
         ///
         /// </summary>
         /// <param name="fullName"></param>
         /// <param name="overwrite">如果表已存在，drop后重新创建（true慎用）</param>
         /// <returns></returns>
         static string GetTableCreateSql(string fullName, bool overwrite = false)
         {
             var type = Type.GetType(fullName);

             var columnDefinitionList = GetColumnDefinitionList(type);

             //数据库 表名
             var tableName = type.Name;
             var dbTableNameAttr = type.GetCustomAttributes(false).Where(attr => attr.GetType().Name == "DBTableNameAttribute").SingleOrDefault() as
     dynamic;
             if (dbTableNameAttr != null)
                 tableName = dbTableNameAttr.Name;
             //主键列
             var primaryKeyArr = (from clmn in columnDefinitionList where clmn.IsPrimaryKey select clmn.ColumnName).ToArray();
             //是否 TEXTIMAGE ON
             var isTextImageOn = type.GetCustomAttributes(false).Where(attr => attr.GetType().Name == "TextImageOn").Any();

             if (!string.IsNullOrWhiteSpace(tableName) && columnDefinitionList.Count > )
             {
                 var sb = new StringBuilder();

                 sb.AppendFormat(@"USE [{0}]
 GO", SchemaName);

                 if (overwrite)
                 {
                     sb.AppendFormat(@"

 if exists (select 1 from  sysobjects where  id = object_id('{0}') and type = 'U')
 drop table {0}
 GO", tableName);
                 }

                 sb.AppendFormat(@"

 /****** Object:  Table [dbo].[{1}]    Script Date: {2}    Generate By CodeFrist  ******/
 SET ANSI_NULLS ON
 GO

 SET QUOTED_IDENTIFIER ON
 GO

 SET ANSI_PADDING ON
 GO

 CREATE TABLE [dbo].[{1}](", SchemaName, tableName, DateTime.Now.ToString("MM/dd/yyyy HH:mm:ss"));

                 columnDefinitionList.ForEach(p =>
                 {
                     //组合主键 不能定义 IDENTITY
                     sb.AppendFormat(@"
     [{0}] [{1}]{2} {3} {4},", p.ColumnName, p.DbType, p.MaxLength >  ? "(" + p.MaxLength + ")" : "", p.IsPrimaryKey && primaryKeyArr.Length <=  ? "IDENTITY(" + p.Seed + "," + p.Incr + ")" : "", p.IsNullable ? "NULL" : "NOT NULL");
                 });

                 if (primaryKeyArr != null && primaryKeyArr.Length > )
                 {
                     //主键列
                     sb.AppendFormat(@"
  CONSTRAINT [PK_{0}] PRIMARY KEY CLUSTERED
 (
     {1}
 )WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
 ", tableName, primaryKeyArr.Aggregate("", (current, cName) => current += string.Format(",[{0}] ASC", cName)).Trim(','));
                 }
                 //else //多余的这个逗号可以不去掉

                 sb.AppendFormat(@"
 ) ON [PRIMARY] {0}

 GO

 SET ANSI_PADDING OFF
 GO
 ", isTextImageOn ? "TEXTIMAGE_ON [PRIMARY]" : "");

                 columnDefinitionList.Where(p => !string.IsNullOrWhiteSpace(p.Description)).ToList().ForEach(p =>
                 {
                     //字段说明
                     sb.AppendFormat(@"
 EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'{2}' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'{0}', @level2type=N'COLUMN',@level2name=N'{1}'
 GO
 ", tableName, p.ColumnName, ToSqlLike(p.Description));
                 });

                 return sb.ToString(); //这个格式和Management Studio生成的sql内容一致

             }

             return string.Empty;
         }

         /// <summary>
         /// 获取所有列定义（此为重点，反射+特性）
         /// </summary>
         /// <param name="type"></param>
         /// <returns></returns>
         static List<ColumnDefinition> GetColumnDefinitionList(Type type)
         {
             var columnDefinitionList = new List<ColumnDefinition>();

             var pInfoArr = type.GetProperties(BindingFlags.Instance | BindingFlags.Public);
             foreach (PropertyInfo pInfo in pInfoArr)
             {
                 var columnDefinition = new ColumnDefinition() { ColumnName = pInfo.Name };

                 Console.WriteLine("----------Property Name:{0}-----------", pInfo.Name);

                 foreach (dynamic attr in pInfo.GetCustomAttributes(false))
                 {
                     var attributeName = attr.GetType().Name as string;

                     var attributeInfoStr = string.Format("Attribute Name:{0}", attributeName);
                     switch (attributeName)
                     {
                         case "PrimaryKeyAttribute":
                             columnDefinition.IsPrimaryKey = true;
                             columnDefinition.Seed = attr.Seed;
                             columnDefinition.Incr = attr.Incr;
                             columnDefinition.IsPrimaryKey = true;
                             Console.WriteLine(attributeInfoStr);
                             break;
                         case "DataTypeAttribute":
                             columnDefinition.DbType = attr.DbType;
                             columnDefinition.MaxLength = attr.MaxLength;
                             attributeInfoStr += string.Format("(DbType:{0}{1})", columnDefinition.DbType, columnDefinition.MaxLength >  ? ",MaxLength:" + columnDefinition.MaxLength : "");
                             Console.WriteLine(attributeInfoStr);
                             break;
                         case "IsNullableAttribute":
                             columnDefinition.IsNullable = true;
                             Console.WriteLine(attributeInfoStr);
                             break;
                         case "DescriptionAttribute":
                             columnDefinition.Description = attr.Description; //字段说明
                             attributeInfoStr += string.Format("(说明:{0})", columnDefinition.Description);
                             Console.WriteLine(attributeInfoStr);
                             break;
                         default:
                             break;
                     }
                 }

                 if (!string.IsNullOrWhiteSpace(columnDefinition.ColumnName) && !string.IsNullOrWhiteSpace(columnDefinition.DbType))
                 {
                     columnDefinitionList.Add(columnDefinition);
                 }

                 Console.WriteLine();
             }

             return columnDefinitionList;
         }

         #region DBHelper

         /// <summary>
         /// check数据库是否已存在，不存在则自动创建
         /// </summary>
         /// <param name="connectionString"></param>
         /// <param name="schemaName"></param>
         static void CheckSchema(string connectionString, string schemaName)
         {
             var pattern = @"Initial\s*Catalog\s*=\s*master";
             Match match = Regex.Match(connectionString, pattern, RegexOptions.IgnoreCase);
             if (match.Groups.Count == )
             {
                 throw new ArgumentException();
             }
             var sql = string.Format(@"
 if not exists(select 1 from sysdatabases where name='{0}')
 create database {0}
 ", schemaName);
             ExcuteSql(connectionString, sql);
         }

         static bool ExcuteSql(string connectionString, string sql)
         {
             try
             {
                 using (var conn = new SqlConnection(connectionString))
                 {
                     conn.Execute(sql);
                 }
                 return true;
             }
             catch (Exception ex)
             {
                 return false;
             }
         }

         /// <summary>
         /// 对字符串进行sql格式化，并且符合like查询的格式。
         /// </summary>
         /// <param name="sqlstr"></param>
         /// <returns></returns>
         static string ToSqlLike(string sqlstr)
         {
             if (string.IsNullOrEmpty(sqlstr)) return string.Empty;
             StringBuilder str = new StringBuilder(sqlstr);
             str.Replace("'", "''");
             str.Replace("[", "[[]");
             str.Replace("%", "[%]");
             str.Replace("_", "[_]");
             return str.ToString();
         }

         #endregion

     }

     /// <summary>
     /// 数据库 列定义
     /// </summary>
     public class ColumnDefinition
     {
         public string ColumnName { get; set; }
         public bool IsPrimaryKey { get; set; }
         /// <summary>
         /// 标示种子
         /// </summary>
         public int Seed { get; set; }
         /// <summary>
         /// 标示增量
         /// </summary>
         public int Incr { get; set; }
         public string DbType { get; set; }
         public int MaxLength { get; set; }
         /// <summary>
         /// true 可为空， 否则 false 不可为空
         /// </summary>
         public bool IsNullable { get; set; }
         public string Description { get; set; }
     }

     #region Custom Attributes

     [AttributeUsage(AttributeTargets.Class)]
     /// <summary>
     /// 数据库 表名
     /// </summary>
     public class DBTableNameAttribute : Attribute
     {
         public string Name { get; set; }
     }

     [AttributeUsage(AttributeTargets.Class)]
     /// <summary>
     /// 表的TEXTIMAGE ON特性
     /// </summary>
     public class TextImageOnAttribute : Attribute
     {

     }

     [AttributeUsage(AttributeTargets.Property)]
     /// <summary>
     /// 主键
     /// </summary>
     public class PrimaryKeyAttribute : Attribute
     {
         /// <summary>
         /// 标示种子
         /// </summary>
         public int Seed { get; set; }
         /// <summary>
         /// 标示增量
         /// </summary>
         public int Incr { get; set; }
     }

     [AttributeUsage(AttributeTargets.Property)]
     /// <summary>
     /// 数据类型
     /// </summary>
     public class DataTypeAttribute : Attribute
     {
         public string DbType { get; set; }
         public int MaxLength { get; set; }
     }

     [AttributeUsage(AttributeTargets.Property)]
     /// <summary>
     /// 允许Null值
     /// </summary>
     public class IsNullableAttribute : Attribute
     {

     }

     #endregion

     #region Table Model

     [TextImageOn]
     /// <summary>
     ///
     /// </summary>
     public class TB_Enterprise
     {
         [PrimaryKey(Seed = , Incr = )]
         [DataType(DbType = "int")]
         public int EnterpriseId { get; set; }

         [DataType(DbType = "int")]
         public int Status { get; set; }

         [DataType(DbType = "int")]
         [IsNullable]
         public int? IsFamous { get; set; }

         [DataType(DbType = "int")]
         [IsNullable]
         public int? CustomerLevel { get; set; }

         [IsNullable]
         [DataType(DbType = "nvarchar", MaxLength = )]
         [Description("企业名称")]
         /// <summary>
         /// 企业名称
         /// </summary>
         public string Name { get; set; }

         [IsNullable]
         [DataType(DbType = "nvarchar", MaxLength = )]
         public string Industry { get; set; }

         [DataType(DbType = "int")]
         [IsNullable]
         public int? Mode { get; set; }

         [DataType(DbType = "int")]
         [IsNullable]
         public int? Scale { get; set; }

         [DataType(DbType = "nvarchar", MaxLength = )]
         [IsNullable]
         public string City { get; set; }

         [DataType(DbType = "nvarchar", MaxLength = )]
         [IsNullable]
         public string WebSite { get; set; }

         [DataType(DbType = "ntext")]
         [IsNullable]
         public string DescText { get; set; }

         [DataType(DbType = "datetime")]
         public DateTime CreateDate { get; set; }

         [DataType(DbType = "datetime")]
         public DateTime ModifyDate { get; set; }

         [DataType(DbType = "datetime")]
         [IsNullable]
         public DateTime? ApproveDate { get; set; }

         [DataType(DbType = "nvarchar", MaxLength = )]
         [IsNullable]
         public string SourceName { get; set; }

         [DataType(DbType = "nvarchar", MaxLength = )]
         [IsNullable]
         public string License { get; set; }

         [DataType(DbType = "varchar", MaxLength = )]
         [IsNullable]
         public string CreateUser { get; set; }

         [DataType(DbType = "varchar", MaxLength = )]
         [IsNullable]
         public string ModifyUser { get; set; }

         [DataType(DbType = "int")]
         [IsNullable]
         public int? ProcessStatus { get; set; }

         [DataType(DbType = "varchar", MaxLength = )]
         [IsNullable]
         public string Abbr { get; set; }

         [DataType(DbType = "varchar", MaxLength = )]
         [IsNullable]
         public string NameInitial { get; set; }

         [DataType(DbType = "float")]
         [IsNullable]
         public decimal? Activity { get; set; }

         [DataType(DbType = "nvarchar", MaxLength = )]
         [IsNullable]
         public string Tags { get; set; }

         [DataType(DbType = "nvarchar", MaxLength = )]
         [IsNullable]
         public string ConsultantName { get; set; }

         [DataType(DbType = "nvarchar", MaxLength = )]
         [IsNullable]
         public string ConsultantComment { get; set; }

         [DataType(DbType = "int")]
         [IsNullable]
         public int? ConsultantId { get; set; }

         [DataType(DbType = "int")]
         [IsNullable]
         public int? DecoratePercent { get; set; }

         [DataType(DbType = "nvarchar", MaxLength = )]
         [IsNullable]
         public string ShortDesc { get; set; }

         [DataType(DbType = "int")]
         [IsNullable]
         public int? CertificationStatus { get; set; }

         [DataType(DbType = "bit")]
         [IsNullable]
         public bool? IsBDRecommended { get; set; }

         [DataType(DbType = "int")]
         [IsNullable]
         public int? ApproveStatus { get; set; }

         [DataType(DbType = "varchar", MaxLength = )]
         [IsNullable]
         public string ApproveResult { get; set; }

         [DataType(DbType = "int")]
         [IsNullable]
         public int? ApproveByUserId { get; set; }
     }

     #endregion

 }