diff --git a/Src/Asp.Net/OracleTest/Demos/5_CodeFirst.cs b/Src/Asp.Net/OracleTest/Demos/5_CodeFirst.cs
index 94fa0f606..7bd5f8d30 100644
--- a/Src/Asp.Net/OracleTest/Demos/5_CodeFirst.cs
+++ b/Src/Asp.Net/OracleTest/Demos/5_CodeFirst.cs
@@ -11,7 +11,7 @@ namespace OrmTest.Demo
      
         [SugarColumn(IsNullable =false ,IsPrimaryKey =true,IsIdentity =true)]
         public int Id { get; set; }
-        [SugarColumn(Length = 21,OldColumnName = "Name2")]
+        [SugarColumn(Length = 21,OldColumnName = "Name2",ColumnDescription ="haha")]
         public string Name{ get; set; }
         [SugarColumn(IsNullable = true,Length =10)]
         public string IsOk { get; set; }
@@ -24,6 +24,7 @@ namespace OrmTest.Demo
         public double? Dob2 { get; set; }
         [SugarColumn(Length =110)]
         public string A1 { get; set; }
+        public string X2 { get; set; }
     }
     public class CodeTable2 {
         public int Id { get; set; }
diff --git a/Src/Asp.Net/SqlSugar/Abstract/CodeFirstProvider/CodeFirstProvider.cs b/Src/Asp.Net/SqlSugar/Abstract/CodeFirstProvider/CodeFirstProvider.cs
index 9bbbb5886..eee4b2c96 100644
--- a/Src/Asp.Net/SqlSugar/Abstract/CodeFirstProvider/CodeFirstProvider.cs
+++ b/Src/Asp.Net/SqlSugar/Abstract/CodeFirstProvider/CodeFirstProvider.cs
@@ -11,7 +11,7 @@ namespace SqlSugar
         public virtual SqlSugarClient Context { get; set; }
         private bool IsBackupTable { get; set; }
         private int MaxBackupDataRows { get; set; }
-        private int DefultLength { get; set; }
+        protected virtual int DefultLength { get; set; }
         #endregion
 
         #region Public methods
@@ -162,8 +162,8 @@ namespace SqlSugar
                 {
                     var dbColumn = dbColumns.FirstOrDefault(dc => dc.DbColumnName.Equals(item.DbColumnName, StringComparison.CurrentCultureIgnoreCase));
                     if (dbColumn == null) continue;
-                    var pkDiff = item.IsPrimarykey != dbColumn.IsPrimarykey;
-                    var idEntityDiff = item.IsIdentity != dbColumn.IsIdentity;
+                    bool pkDiff, idEntityDiff;
+                    KeyAction(item, dbColumn, out pkDiff, out idEntityDiff);
                     if (dbColumn != null && pkDiff && !idEntityDiff)
                     {
                         var isAdd = item.IsPrimarykey;
@@ -188,6 +188,12 @@ namespace SqlSugar
             }
         }
 
+        protected virtual void KeyAction(EntityColumnInfo item, DbColumnInfo dbColumn, out bool pkDiff, out bool idEntityDiff)
+        {
+            pkDiff = item.IsPrimarykey != dbColumn.IsPrimarykey;
+            idEntityDiff = item.IsIdentity != dbColumn.IsIdentity;
+        }
+
         protected virtual void ChangeKey(EntityInfo entityInfo, string tableName, EntityColumnInfo item)
         {
             string constraintName = string.Format("PK_{0}_{1}", tableName, item.DbColumnName);
diff --git a/Src/Asp.Net/SqlSugar/Realization/Oracle/CodeFirst/OracleCodeFirst.cs b/Src/Asp.Net/SqlSugar/Realization/Oracle/CodeFirst/OracleCodeFirst.cs
index 82a43712b..3d7cafbe2 100644
--- a/Src/Asp.Net/SqlSugar/Realization/Oracle/CodeFirst/OracleCodeFirst.cs
+++ b/Src/Asp.Net/SqlSugar/Realization/Oracle/CodeFirst/OracleCodeFirst.cs
@@ -7,6 +7,12 @@ namespace SqlSugar
 {
     public class OracleCodeFirst : CodeFirstProvider
     {
+        public OracleCodeFirst() {
+            if (DefultLength == 0)
+                DefultLength = 40;
+        }
+        protected override int DefultLength { get; set; }
+
         protected override void GetDbType(EntityColumnInfo item, Type propertyType, DbColumnInfo result)
         {
             if (!string.IsNullOrEmpty(item.DataType))
@@ -29,5 +35,11 @@ namespace SqlSugar
                 }
             }
         }
+
+        protected override void KeyAction(EntityColumnInfo item, DbColumnInfo dbColumn, out bool pkDiff, out bool idEntityDiff)
+        {
+            pkDiff = item.IsPrimarykey != dbColumn.IsPrimarykey;
+            idEntityDiff = false;
+        }
     }
 }
diff --git a/Src/Asp.Net/SqlSugar/Realization/Oracle/DbMaintenance/OracleDbMaintenance.cs b/Src/Asp.Net/SqlSugar/Realization/Oracle/DbMaintenance/OracleDbMaintenance.cs
index 035a66ae1..d239b8d45 100644
--- a/Src/Asp.Net/SqlSugar/Realization/Oracle/DbMaintenance/OracleDbMaintenance.cs
+++ b/Src/Asp.Net/SqlSugar/Realization/Oracle/DbMaintenance/OracleDbMaintenance.cs
@@ -55,14 +55,14 @@ namespace SqlSugar
         {
             get
             {
-                return "ALTER 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 "ALTER TABLE {0} ALTER COLUMN {1} {2}{3} {4} {5} {6}";
+                return "ALTER TABLE {0} modify ({1} {2}{3} {4} {5} {6}) ";
             }
         }
         protected override string BackupDataBaseSql
@@ -145,14 +145,14 @@ namespace SqlSugar
         {
             get
             {
-                return "NULL";
+                return "";
             }
         }
         protected override string CreateTableNotNull
         {
             get
             {
-                return "NOT NULL";
+                return "";
             }
         }
         protected override string CreateTablePirmaryKey
@@ -174,7 +174,7 @@ namespace SqlSugar
         {
             get
             {
-                return "comment on column {1}.{0} is '{2}';";
+                return "comment on column {1}.{0} is '{2}'";
             }
         }
 
@@ -182,7 +182,7 @@ namespace SqlSugar
         {
             get
             {
-                return "comment on column {1}.{0} is '';";
+                return "comment on column {1}.{0} is ''";
             }
         }
 
@@ -198,7 +198,7 @@ namespace SqlSugar
         {
             get
             {
-                return "comment on table {0}  is  '{1}';";
+                return "comment on table {0}  is  '{1}'";
             }
         }
 
@@ -206,7 +206,7 @@ namespace SqlSugar
         {
             get
             {
-                return "comment on table {0}  is  '';";
+                return "comment on table {0}  is  ''";
             }
         }
 
@@ -220,6 +220,43 @@ namespace SqlSugar
         #endregion
 
         #region Methods
+        public override bool AddRemark(EntityInfo entity)
+        {
+            var db = this.Context;
+            var columns = entity.Columns.Where(it => it.IsIgnore == false).ToList();
+
+            foreach (var item in columns)
+            {
+                if (item.ColumnDescription != null)
+                {
+                    //column remak
+                    if (db.DbMaintenance.IsAnyColumnRemark(item.DbColumnName.ToUpper(), item.DbTableName.ToUpper()))
+                    {
+                        db.DbMaintenance.DeleteColumnRemark(item.DbColumnName.ToUpper(), item.DbTableName.ToUpper());
+                        db.DbMaintenance.AddColumnRemark(item.DbColumnName.ToUpper(), item.DbTableName.ToUpper(), item.ColumnDescription);
+                    }
+                    else
+                    {
+                        db.DbMaintenance.AddColumnRemark(item.DbColumnName.ToUpper(), item.DbTableName.ToUpper(), item.ColumnDescription);
+                    }
+                }
+            }
+
+            //table remak
+            if (entity.TableDescription != null)
+            {
+                if (db.DbMaintenance.IsAnyTableRemark(entity.DbTableName))
+                {
+                    db.DbMaintenance.DeleteTableRemark(entity.DbTableName);
+                    db.DbMaintenance.AddTableRemark(entity.DbTableName, entity.TableDescription);
+                }
+                else
+                {
+                    db.DbMaintenance.AddTableRemark(entity.DbTableName, entity.TableDescription);
+                }
+            }
+            return true;
+        }
         public override List<DbColumnInfo> GetColumnInfosByTableName(string tableName,bool isCache=true)
         {
             string cacheKey = "DbMaintenanceProvider.GetColumnInfosByTableName." + this.SqlBuilder.GetNoTranslationColumnName(tableName).ToLower();