Update exp to sql

Src/Asp.NetCore2/SqlSeverTest/SqlSeverTest/UnitTest/UQueryable.cs

@@ -102,6 +102,21 @@ namespace OrmTest
                 a = string.IsNullOrEmpty(it.Name)
             }).ToList();
 
+            var blist4 = Db.Queryable<BoolTest3>().Select(it => new BoolTest3()
+            {
+                a = SqlFunc.IIF(it.a == true, true, false)
+            }).ToList();
+
+
+            var blist5 = Db.Queryable<BoolTest3>().Select(it => new BoolTest3()
+            {
+                a = SqlFunc.IF(it.a == true).Return(true).End(false)
+            }).ToList();
+
+            var blist6 = Db.Queryable<BoolTest3>().Select(it => new BoolTest3()
+            {
+                a =it.a==true?true:false
+            }).ToList();
             var db = Db;
             db.CodeFirst.InitTables<UserInfo, UserIpRuleInfo>();
             db.Deleteable<UserInfo>().ExecuteCommand();

Src/Asp.NetCore2/SqlSeverTest/SqlSugar/ExpressionsToSql/ResolveItems/BaseResolve.cs

@@ -477,19 +477,19 @@ namespace SqlSugar
                     {
                         asName = GetAsNameAndShortName(item, shortName, property);
                     }
-                    else 
+                    else
                     {
                         asName = GetAsName(item, shortName, property);
                     }
                 }
             }
-            else if (item.Type == UtilConstants.BoolType && item is MethodCallExpression)
+            else if (item.Type == UtilConstants.BoolType && item is MethodCallExpression && IsNotCaseExpression(item))
             {
                 this.Expression = item;
                 this.Start();
                 var sql= this.Context.DbMehtods.IIF(new MethodCallExpressionModel()
                 {
-                     Args=new List<MethodCallExpressionArgs>() {
+                    Args=new List<MethodCallExpressionArgs>() {
                           new MethodCallExpressionArgs() {
                                IsMember=true,
                                MemberName=parameter.CommonTempData.ObjToString()
@@ -518,6 +518,22 @@ namespace SqlSugar
             }
         }
 
+        private static bool IsNotCaseExpression(Expression item)
+        {
+            if ((item as MethodCallExpression).Method.Name == "IIF")
+            {
+                return false;
+            }
+            else if ((item as MethodCallExpression).Method.Name == "End"&&item.ToString().Contains("IF("))
+            {
+                return false;
+            }
+            else 
+            {
+                return true;
+            }
+        }
+
         private Dictionary<string, string> GetMappingColumns(Expression currentExpression)
         {
             Dictionary<string, string> result = new Dictionary<string, string>();