diff --git a/Src/Asp.NetCore2/SqlSugar/Realization/Dm/CodeFirst/DmCodeFirst.cs b/Src/Asp.NetCore2/SqlSugar/Realization/Dm/CodeFirst/DmCodeFirst.cs
index 143e79240..3a14da721 100644
--- a/Src/Asp.NetCore2/SqlSugar/Realization/Dm/CodeFirst/DmCodeFirst.cs
+++ b/Src/Asp.NetCore2/SqlSugar/Realization/Dm/CodeFirst/DmCodeFirst.cs
@@ -50,6 +50,32 @@ namespace SqlSugar
             }
             return result;
         }
+        protected override void GetDbType(EntityColumnInfo item, Type propertyType, DbColumnInfo result)
+        {
+            if (!string.IsNullOrEmpty(item.DataType))
+            {
+                result.DataType = item.DataType;
+            }
+            else if (propertyType.IsEnum())
+            {
+                result.DataType = this.Context.Ado.DbBind.GetDbTypeName(item.Length > 9 ? UtilConstants.LongType.Name : UtilConstants.IntType.Name);
+            }
+            else
+            {
+                if (propertyType.Name.Equals("Guid", StringComparison.CurrentCultureIgnoreCase))
+                {
+                    result.DataType = this.Context.Ado.DbBind.GetDbTypeName(UtilConstants.StringType.Name);
+                    if (result.Length <= 1)
+                    {
+                        result.Length = 36;
+                    }
+                }
+                else
+                {
+                    result.DataType = this.Context.Ado.DbBind.GetDbTypeName(propertyType.Name);
+                }
+            }
+        }
 
         protected override void ConvertColumns(List<DbColumnInfo> dbColumns)
         {
diff --git a/Src/Asp.NetCore2/SqlSugar/Realization/Dm/DbBind/DmDbBind.cs b/Src/Asp.NetCore2/SqlSugar/Realization/Dm/DbBind/DmDbBind.cs
index 7e59503d8..a13d912f5 100644
--- a/Src/Asp.NetCore2/SqlSugar/Realization/Dm/DbBind/DmDbBind.cs
+++ b/Src/Asp.NetCore2/SqlSugar/Realization/Dm/DbBind/DmDbBind.cs
@@ -18,6 +18,8 @@ namespace SqlSugar
                 csharpTypeName = "long";
             if (csharpTypeName.ToLower().IsIn("boolean", "bool"))
                 csharpTypeName = "bool";
+            if (csharpTypeName == "Guid")
+                csharpTypeName = "string";
             if (csharpTypeName == "DateTimeOffset")
                 csharpTypeName = "DateTime";
             var mappings = this.MappingTypes.Where(it => it.Value.ToString().Equals(csharpTypeName, StringComparison.CurrentCultureIgnoreCase));
diff --git a/Src/Asp.NetCore2/SqlSugar/Realization/Oracle/CodeFirst/OracleCodeFirst.cs b/Src/Asp.NetCore2/SqlSugar/Realization/Oracle/CodeFirst/OracleCodeFirst.cs
index 3d7cafbe2..0f8d499eb 100644
--- a/Src/Asp.NetCore2/SqlSugar/Realization/Oracle/CodeFirst/OracleCodeFirst.cs
+++ b/Src/Asp.NetCore2/SqlSugar/Realization/Oracle/CodeFirst/OracleCodeFirst.cs
@@ -28,6 +28,10 @@ namespace SqlSugar
                 if (propertyType.Name.Equals("Guid", StringComparison.CurrentCultureIgnoreCase))
                 {
                     result.DataType = this.Context.Ado.DbBind.GetDbTypeName(UtilConstants.StringType.Name);
+                    if (result.Length <= 1)
+                    {
+                        result.Length = 36;
+                    }
                 }
                 else
                 {