diff --git a/SqlServerTest/Demos/5_CodeFirst.cs b/SqlServerTest/Demos/5_CodeFirst.cs
index afcfc756d..3778dbe5c 100644
--- a/SqlServerTest/Demos/5_CodeFirst.cs
+++ b/SqlServerTest/Demos/5_CodeFirst.cs
@@ -10,7 +10,7 @@ namespace OrmTest.Demo
     {
         [SugarColumn(IsPrimaryKey = true, IsIdentity = true)]
         public int Id { get; set; }
-        [SugarColumn(Length = 40)]
+        [SugarColumn(Length = 100)]
         public string Name { get; set; }
         [SugarColumn(IsNullable = true)]
         public bool IsOk { get; set; }
diff --git a/SqlSugar/Abstract/DbFirstProvider/DbFirstProvider.cs b/SqlSugar/Abstract/DbFirstProvider/DbFirstProvider.cs
index 61075776c..94f8e5bfb 100644
--- a/SqlSugar/Abstract/DbFirstProvider/DbFirstProvider.cs
+++ b/SqlSugar/Abstract/DbFirstProvider/DbFirstProvider.cs
@@ -122,6 +122,7 @@ namespace SqlSugar
         }
         #endregion
 
+        #region Core
         public Dictionary<string, string> ToClassStringList(string nameSpace = "Models")
         {
             this.Namespace = nameSpace;
@@ -150,7 +151,7 @@ namespace SqlSugar
                     classText = classText.Replace(DbFirstTemplate.KeyNamespace, this.Namespace);
                     classText = classText.Replace(DbFirstTemplate.KeyUsing, IsAttribute ? (this.UsingTemplate + "using " + PubConst.AssemblyName + ";\r\n") : this.UsingTemplate);
                     classText = classText.Replace(DbFirstTemplate.KeyClassDescription, this.ClassDescriptionTemplate.Replace(DbFirstTemplate.KeyClassDescription, tableInfo.Description + "\r\n"));
-                    classText = classText.Replace(DbFirstTemplate.KeySugarTable, IsAttribute ? string.Format(DbFirstTemplate.ValueSugarTable, tableInfo.Name): null);
+                    classText = classText.Replace(DbFirstTemplate.KeySugarTable, IsAttribute ? string.Format(DbFirstTemplate.ValueSugarTable, tableInfo.Name) : null);
                     if (columns.IsValuable())
                     {
                         foreach (var item in columns)
@@ -183,7 +184,21 @@ namespace SqlSugar
             }
             return result;
         }
+        public void CreateClassFile(string directoryPath, string nameSpace = "Models")
+        {
+            Check.ArgumentNullException(directoryPath, "directoryPath can't null");
+            var classStringList = ToClassStringList(nameSpace);
+            if (classStringList.IsValuable())
+            {
+                foreach (var item in classStringList)
+                {
+                    FileHelper.CreateFile(directoryPath.TrimEnd('\\').TrimEnd('/') + string.Format("\\{0}.cs", item.Key), item.Value, Encoding.UTF8);
+                }
+            }
+        } 
+        #endregion
 
+        #region Private methods
         private string GetProertypeDefaultValue(DbColumnInfo item)
         {
             var result = item.DefaultValue;
@@ -203,21 +218,6 @@ namespace SqlSugar
             result = result.Replace("\r", "\t").Replace("\n", "\t");
             return result;
         }
-
-        public void CreateClassFile(string directoryPath, string nameSpace = "Models")
-        {
-            Check.ArgumentNullException(directoryPath, "directoryPath can't null");
-            var classStringList = ToClassStringList(nameSpace);
-            if (classStringList.IsValuable())
-            {
-                foreach (var item in classStringList)
-                {
-                    FileHelper.CreateFile(directoryPath.TrimEnd('\\').TrimEnd('/') + string.Format("\\{0}.cs", item.Key), item.Value, Encoding.UTF8);
-                }
-            }
-        }
-
-        #region Private methods
         private string GetPropertyText(DbColumnInfo item, string PropertyText)
         {
             string SugarColumnText = DbFirstTemplate.ValueSugarCoulmn;
@@ -266,7 +266,6 @@ namespace SqlSugar
                 return item.DbColumnName;
             }
         }
-
         private string GetPropertyTypeName(DbColumnInfo item)
         {
             string result = this.Context.Ado.DbBind.GetPropertyTypeName(item.DataType);
@@ -283,7 +282,6 @@ namespace SqlSugar
             string result = this.Context.Ado.DbBind.GetConvertString(item.DataType) + "(\"" + convertString + "\")";
             return result;
         }
-
         private string GetPropertyDescriptionText(DbColumnInfo item, string propertyDescriptionText)
         {
             propertyDescriptionText = propertyDescriptionText.Replace(DbFirstTemplate.KeyPropertyDescription, item.ColumnDescription);
@@ -291,7 +289,6 @@ namespace SqlSugar
             propertyDescriptionText = propertyDescriptionText.Replace(DbFirstTemplate.KeyIsNullable, item.IsNullable.ObjToString());
             return propertyDescriptionText;
         }
-
         #endregion
     }
 }
diff --git a/SqlSugar/Interface/IDbMaintenance.cs b/SqlSugar/Interface/IDbMaintenance.cs
index c677db668..6dd2bf416 100644
--- a/SqlSugar/Interface/IDbMaintenance.cs
+++ b/SqlSugar/Interface/IDbMaintenance.cs
@@ -10,13 +10,9 @@ namespace SqlSugar
 
         #region DML
         List<DbTableInfo> GetViewInfoList();
-
         List<DbTableInfo> GetTableInfoList();
-
         List<DbColumnInfo> GetColumnInfosByTableName(string tableName);
-
         List<string> GetIsIdentities(string tableName);
-
         List<string> GetPrimaries(string tableName);
         #endregion
 
@@ -30,11 +26,9 @@ namespace SqlSugar
         #region DDL
         bool DropTable(string tableName);
         bool TruncateTable(string tableName);
-
         bool CreateTable(string tableName, List<DbColumnInfo> columns);
-
         bool AddColumnToTable(string tableName, DbColumnInfo column);
-
+        bool AddKey(string tableName,string columnName,bool isPrimaryKey, bool isIdentity);
         bool BackupDataBase(string databaseName,string fullFileName);
         bool DropColumn(string tableName,string columnName);
         #endregion
diff --git a/SqlSugar/Realization/SqlServer/DbMaintenance/SqlServerDbMaintenance.cs b/SqlSugar/Realization/SqlServer/DbMaintenance/SqlServerDbMaintenance.cs
index 5ea1682df..f1640f2e7 100644
--- a/SqlSugar/Realization/SqlServer/DbMaintenance/SqlServerDbMaintenance.cs
+++ b/SqlSugar/Realization/SqlServer/DbMaintenance/SqlServerDbMaintenance.cs
@@ -79,14 +79,14 @@ namespace SqlSugar
         {
             get
             {
-                return "ALERT TABLE {0} ADD {1} {2}{3} {4} {5} {6}";
+                return "ALTER TABLE {0} ADD {1} {2}{3} {4} {5} {6}";
             }
         }
         protected override string AlterColumnToTableSql
         {
             get
             {
-                return "ALERT TABLE {0} ALTER COLUMN {1}{2} {3} ";
+                return "ALTER TABLE {0} ALTER COLUMN {1}{2} {3} ";
             }
         }
         protected override string BackupDataBaseSql