diff --git a/OrmTest/UnitTest/ExpressionTest/Method.cs b/OrmTest/UnitTest/ExpressionTest/Method.cs
index 18c328e5f..49cbd3a01 100644
--- a/OrmTest/UnitTest/ExpressionTest/Method.cs
+++ b/OrmTest/UnitTest/ExpressionTest/Method.cs
@@ -48,14 +48,14 @@ namespace OrmTest.UnitTest
         private void DateValue()
         {
             var x2 = DateTime.Now;
-            Expression<Func<Student, bool>> exp = it => NBORM.DateValue(x2,DateType.Year);
+            Expression<Func<Student, bool>> exp = it => NBORM.DateValue(x2,DateType.Year)==1;
             SqlServerExpressionContext expContext = new SqlServerExpressionContext();
             expContext.Resolve(exp, ResolveExpressType.WhereSingle);
             var value = expContext.Result.GetString();
             var pars = expContext.Parameters;
-            base.Check(value, pars, "  (@MethodConst1(@MethodConst0)) ", new List<SugarParameter>() {
-                new SugarParameter("@MethodConst0",x2),new SugarParameter("@MethodConst1",DateType.Year)
-            }, "StartsWith");
+            base.Check(value, pars, " ((@MethodConst1(@MethodConst0)) = @Const2 ) ", new List<SugarParameter>() {
+                new SugarParameter("@MethodConst0",x2),new SugarParameter("@MethodConst1",DateType.Year),new SugarParameter("@Const2",1)
+            }, "DateValue");
         }
 
         private void StartsWith()
@@ -95,26 +95,26 @@ namespace OrmTest.UnitTest
         private void DateAddByType()
         {
             var x2 = DateTime.Now;
-            Expression<Func<Student, bool>> exp = it => NBORM.DateAdd(x2, 11, DateType.Millisecond);
+            Expression<Func<Student, bool>> exp = it => NBORM.DateAdd(x2, 11, DateType.Millisecond)==x2;
             SqlServerExpressionContext expContext = new SqlServerExpressionContext();
             expContext.Resolve(exp, ResolveExpressType.WhereSingle);
             var value = expContext.Result.GetString();
             var pars = expContext.Parameters;
-            base.Check(value, pars, " (DATEADD(@MethodConst2,@MethodConst1,@MethodConst0)) ", new List<SugarParameter>() {
-                new SugarParameter("@MethodConst0",x2),new SugarParameter("@MethodConst1",11),
+            base.Check(value, pars, "((DATEADD(@MethodConst2,@MethodConst1,@MethodConst0)) = @Const3 )", new List<SugarParameter>() {
+                new SugarParameter("@MethodConst0",x2),new SugarParameter("@MethodConst1",11),new SugarParameter("@Const3",x2),
                 new SugarParameter("@MethodConst2",DateType.Millisecond)
             }, "DateAddByType");
         }
         private void DateAddDay()
         {
             var x2 = DateTime.Now;
-            Expression<Func<Student, bool>> exp = it => NBORM.DateAdd(x2, 1);
+            Expression<Func<Student, bool>> exp = it => NBORM.DateAdd(x2, 1)==x2;
             SqlServerExpressionContext expContext = new SqlServerExpressionContext();
             expContext.Resolve(exp, ResolveExpressType.WhereSingle);
             var value = expContext.Result.GetString();
             var pars = expContext.Parameters;
-            base.Check(value, pars, " (DATEADD(day,@MethodConst1,@MethodConst0)) ", new List<SugarParameter>() {
-                new SugarParameter("@MethodConst0",x2),new SugarParameter("@MethodConst1",1)
+            base.Check(value, pars, "((DATEADD(day,@MethodConst1,@MethodConst0)) = @Const2 )", new List<SugarParameter>() {
+                new SugarParameter("@MethodConst0",x2),new SugarParameter("@MethodConst1",1),new SugarParameter("@Const2",x2)
             }, "DateIsSameByType");
         }
 
diff --git a/SqlSugar/ExpressionsToSql/Method/DefaultDbMethod.cs b/SqlSugar/ExpressionsToSql/Method/DefaultDbMethod.cs
index b4fadb485..697be7d37 100644
--- a/SqlSugar/ExpressionsToSql/Method/DefaultDbMethod.cs
+++ b/SqlSugar/ExpressionsToSql/Method/DefaultDbMethod.cs
@@ -13,46 +13,46 @@ namespace SqlSugar
             return string.Format("( {0}='' OR {0} IS NULL )", parameter.Value);
         }
 
-        public virtual object ToUpper(MethodCallExpressionModel model)
+        public virtual string ToUpper(MethodCallExpressionModel model)
         {
             var parameter = model.Args[0];
             return string.Format(" (UPPER({0})) ", parameter.Value);
         }
 
-        public virtual object ToLower(MethodCallExpressionModel model)
+        public virtual string ToLower(MethodCallExpressionModel model)
         {
             var parameter = model.Args[0];
             return string.Format(" (LOWER({0})) ", parameter.Value);
         }
 
-        public virtual object Trim(MethodCallExpressionModel model)
+        public virtual string Trim(MethodCallExpressionModel model)
         {
             var parameter = model.Args[0];
             return string.Format(" (rtrim(ltrim({0}))) ", parameter.Value);
         }
 
-        public virtual object Contains(MethodCallExpressionModel model)
+        public virtual string Contains(MethodCallExpressionModel model)
         {
             var parameter = model.Args[0];
             var parameter2 = model.Args[1];
             return string.Format(" ({0} like '%'+{1}+'%') ", parameter.Value, parameter2.Value);
         }
 
-        public object Equals(MethodCallExpressionModel model)
+        public string Equals(MethodCallExpressionModel model)
         {
             var parameter = model.Args[0];
             var parameter2 = model.Args[1];
             return string.Format(" ({0} = {1}) ", parameter.Value, parameter2.Value); ;
         }
 
-        public object DateIsSameDay(MethodCallExpressionModel model)
+        public string DateIsSameDay(MethodCallExpressionModel model)
         {
             var parameter = model.Args[0];
             var parameter2 = model.Args[1];
             return string.Format(" (DATEDIFF(day,{0},{1})=0) ", parameter.Value, parameter2.Value); ;
         }
 
-        public object DateIsSameByType(MethodCallExpressionModel model)
+        public string DateIsSameByType(MethodCallExpressionModel model)
         {
             var parameter = model.Args[0];
             var parameter2 = model.Args[1];
@@ -60,7 +60,7 @@ namespace SqlSugar
             return string.Format(" (DATEDIFF({2},{0},{1})=0) ", parameter.Value, parameter2.Value, parameter3.Value); 
         }
 
-        public object DateAddByType(MethodCallExpressionModel model)
+        public string DateAddByType(MethodCallExpressionModel model)
         {
             var parameter = model.Args[0];
             var parameter2 = model.Args[1];
@@ -68,14 +68,14 @@ namespace SqlSugar
             return string.Format(" (DATEADD({2},{1},{0})) ", parameter.Value, parameter2.Value, parameter3.Value);
         }
 
-        public object DateAddDay(MethodCallExpressionModel model)
+        public string DateAddDay(MethodCallExpressionModel model)
         {
             var parameter = model.Args[0];
             var parameter2 = model.Args[1];
             return string.Format(" (DATEADD(day,{1},{0})) ", parameter.Value, parameter2.Value); 
         }
 
-        public object Between(MethodCallExpressionModel model)
+        public string Between(MethodCallExpressionModel model)
         {
             var parameter = model.Args[0];
             var parameter1 = model.Args[1];
@@ -83,21 +83,21 @@ namespace SqlSugar
             return string.Format(" ({0} BETWEEN {1} AND {2}) ", parameter.Value, parameter1.Value, parameter2.Value);
         }
 
-        public object StartsWith(MethodCallExpressionModel model)
+        public string StartsWith(MethodCallExpressionModel model)
         {
             var parameter = model.Args[0];
             var parameter2 = model.Args[1];
             return string.Format(" ({0} like {1}+'%') ", parameter.Value, parameter2.Value);
         }
 
-        public object EndsWith(MethodCallExpressionModel model)
+        public string EndsWith(MethodCallExpressionModel model)
         {
             var parameter = model.Args[0];
             var parameter2 = model.Args[1];
             return string.Format(" ({0} like '%'+{1}) ", parameter.Value, parameter2.Value);
         }
 
-        public object DateValue(MethodCallExpressionModel model)
+        public string DateValue(MethodCallExpressionModel model)
         {
             var parameter = model.Args[0];
             var parameter2 = model.Args[1];
diff --git a/SqlSugar/ExpressionsToSql/Method/IDbMethods.cs b/SqlSugar/ExpressionsToSql/Method/IDbMethods.cs
index d678a0e59..efad1b8c3 100644
--- a/SqlSugar/ExpressionsToSql/Method/IDbMethods.cs
+++ b/SqlSugar/ExpressionsToSql/Method/IDbMethods.cs
@@ -12,18 +12,18 @@ namespace SqlSugar
     public interface IDbMethods
     {
         string IsNullOrEmpty(MethodCallExpressionModel model);
-        object ToLower(MethodCallExpressionModel model);
-        object ToUpper(MethodCallExpressionModel model);
-        object Trim(MethodCallExpressionModel model);
-        object Contains(MethodCallExpressionModel model);
-        object Equals(MethodCallExpressionModel model);
-        object DateIsSameDay(MethodCallExpressionModel model);
-        object DateIsSameByType(MethodCallExpressionModel model);
-        object DateAddByType(MethodCallExpressionModel model);
-        object DateValue(MethodCallExpressionModel model);
-        object DateAddDay(MethodCallExpressionModel model);
-        object Between(MethodCallExpressionModel model);
-        object StartsWith(MethodCallExpressionModel model);
-        object EndsWith(MethodCallExpressionModel model);
+        string ToLower(MethodCallExpressionModel model);
+        string ToUpper(MethodCallExpressionModel model);
+        string Trim(MethodCallExpressionModel model);
+        string Contains(MethodCallExpressionModel model);
+        string Equals(MethodCallExpressionModel model);
+        string DateIsSameDay(MethodCallExpressionModel model);
+        string DateIsSameByType(MethodCallExpressionModel model);
+        string DateAddByType(MethodCallExpressionModel model);
+        string DateValue(MethodCallExpressionModel model);
+        string DateAddDay(MethodCallExpressionModel model);
+        string Between(MethodCallExpressionModel model);
+        string StartsWith(MethodCallExpressionModel model);
+        string EndsWith(MethodCallExpressionModel model);
     }
 }