-

OrmTest/ExpressionTest/Method.cs

@@ -21,13 +21,30 @@ namespace OrmTest.ExpressionTest
             base.Begin();
             for (int i = 0; i < base.Count; i++)
             {
+                #region StringIsNullOrEmpty
                 StringIsNullOrEmpty();
                 StringIsNullOrEmpty2();
                 StringIsNullOrEmpty3();
                 StringIsNullOrEmpty4();
+                ToUpper();
+                #endregion
             }
             base.End("Method Test");
         }
+
+        private void ToUpper()
+        {
+            Expression<Func<Student, bool>> exp = it =>"a"== NBORM.ToLower(it.Id) ;
+            SqlServerExpressionContext expContext = new SqlServerExpressionContext(exp, ResolveExpressType.WhereSingle);
+            expContext.Resolve();
+            var value = expContext.Result.GetString();
+            var pars = expContext.Parameters;
+            base.Check(value, pars, "(( Id  > @Id0 )  OR  ( Id='' OR Id IS NULL ))", new List<SugarParameter>() {
+                new SugarParameter("@Id0",2)
+            }, "StringIsNullOrEmpty");
+        }
+
+        #region StringIsNullOrEmpty
         private void StringIsNullOrEmpty()
         {
             Expression<Func<Student, bool>> exp = it => it.Id > 2 || NBORM.IsNullOrEmpty(it.Id); ;
@@ -39,7 +56,6 @@ namespace OrmTest.ExpressionTest
                 new SugarParameter("@Id0",2)
             }, "StringIsNullOrEmpty");
         }
-
         private void StringIsNullOrEmpty2()
         {
             Expression<Func<Student, bool>> exp = it => 2 == it.Id || NBORM.IsNullOrEmpty(true); ;
@@ -65,7 +81,6 @@ namespace OrmTest.ExpressionTest
                 new SugarParameter("@Id0",2)
             }, "StringIsNullOrEmpty3");
         }
-
         private void StringIsNullOrEmpty4()
         {
             WhereConst.name = "xx";
@@ -79,6 +94,7 @@ namespace OrmTest.ExpressionTest
                 new SugarParameter("@Id0",2)
             }, "StringIsNullOrEmpty4");
         } 
+        #endregion
     }
 }
 

SqlSugar/ExpressionsToSql/Method/DefaultDbMethod.cs

@@ -12,5 +12,17 @@ namespace SqlSugar
             var parameter = model.Args[0];
             return string.Format("( {0}='' OR {0} IS NULL )", parameter.Value);
         }
+
+        public object ToUpper(MethodCallExpressionModel model)
+        {
+            var parameter = model.Args[0];
+            return string.Format(" (UPPER({0})) ", parameter.Value);
+        }
+
+        public object ToLower(MethodCallExpressionModel model)
+        {
+            var parameter = model.Args[0];
+            return string.Format(" (LOWER({0})) ", parameter.Value);
+        }
     }
 }

SqlSugar/ExpressionsToSql/Method/IDbMethods.cs

@@ -12,5 +12,7 @@ namespace SqlSugar
     public interface IDbMethods
     {
         string IsNullOrEmpty(MethodCallExpressionModel model);
+        object ToLower(MethodCallExpressionModel model);
+        object ToUpper(MethodCallExpressionModel model);
     }
 }

SqlSugar/ExpressionsToSql/ResolveItems/MethodCallExpressionResolve.cs

@@ -67,6 +67,8 @@ namespace SqlSugar
             {
                 case "IsNullOrEmpty":
                     return this.Context.DbMehtods.IsNullOrEmpty(model);
+                case "ToLower":
+                    return this.Context.DbMehtods.ToLower(model);
                 default:
                     break;
             }