Update exp to sql

Src/Asp.Net/SqlServerTest/Demos/1_Query.cs

@@ -716,6 +716,7 @@ namespace OrmTest.Demo
         {
             var db = GetInstance();
             var list = db.Queryable<StudentEnum>().AS("Student").Where(it => it.SchoolId == SchoolEnum.HarvardUniversity).ToList();
+            var list2 = db.Queryable<StudentEnum>().AS("Student").Where(it => it.Name == SchoolEnum.HarvardUniversity.ToString()).ToList();
         }
     }
 }

Src/Asp.Net/SqlSugar/ExpressionsToSql/Common/MethodCallExpressionModel.cs

@@ -9,6 +9,7 @@ namespace SqlSugar
     public class MethodCallExpressionModel
     {
       public List<MethodCallExpressionArgs> Args { get; set; }
+        public string Name { get; internal set; }
     }
 
     public class MethodCallExpressionArgs

Src/Asp.Net/SqlSugar/ExpressionsToSql/ResolveItems/MethodCallExpressionResolve.cs

@@ -172,6 +172,7 @@ namespace SqlSugar
             var method = express.Method;
             var args = express.Arguments.Cast<Expression>().ToList();
             MethodCallExpressionModel model = new MethodCallExpressionModel();
+            model.Name = name;
             model.Args = new List<MethodCallExpressionArgs>();
             switch (this.Context.ResolveType)
             {
@@ -407,7 +408,12 @@ namespace SqlSugar
             {
                 parameter.CommonTempData = DateTime.Now.Date;
             }
-            else {
+            else if (model.Name == "ToString"&&item is ConstantExpression&&(item as ConstantExpression).Type.IsEnum())
+            {
+                parameter.CommonTempData = item.ToString();
+            }
+            else
+            {
                 base.Start();
             }
             var methodCallExpressionArgs = new MethodCallExpressionArgs()