4.6.0.1

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

@@ -232,6 +232,12 @@ namespace OrmTest.Demo
             var getDay1List = db.Queryable<Student>().Where(it => it.CreateTime.Value.Hour == 1).ToList();
             var getDateAdd = db.Queryable<Student>().Where(it => it.CreateTime.Value.AddDays(1) == DateTime.Now).ToList();
             var getDateIsSame = db.Queryable<Student>().Where(it => SqlFunc.DateIsSame(DateTime.Now, DateTime.Now, DateType.Hour)).ToList();
+            var test2 = db.Queryable<Student, School>((st, sc) => st.SchoolId == sc.Id)
+              .Where(st =>
+                SqlFunc.IF(st.Id > 1)
+                     .Return(st.Id)
+                     .ElseIF(st.Id == 1)
+                     .Return(st.SchoolId).End(st.Id) == 1).Select(st => st).ToList();
         }
         public static void Page()
         {

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

@@ -289,7 +289,7 @@ namespace OrmTest.Demo
                         SqlFunc.IF(st.Id > 1)
                              .Return(st.Id)
                              .ElseIF(st.Id == 1)
-                             .Return(st.SchoolId).End(st.Id) == 1).ToList();
+                             .Return(st.SchoolId).End(st.Id) == 1).Select(st=>st).ToList();
             var test3 = db.Queryable<DataTestInfo2>().Select(it => it.Bool1).ToSql();
             var test4 = db.Queryable<DataTestInfo2>().Select(it => new { b=it.Bool1 }).ToSql();
         }

Src/Asp.Net/SqlSugar/ExpressionsToSql/CaseWhen/CaseWhenResolve.cs

@@ -16,7 +16,6 @@ namespace SqlSugar
     {
         List<MethodCallExpression> allMethods = new List<MethodCallExpression>();
         private ExpressionContext context = null;
-        private bool hasWhere;
         public CaseWhenResolve(MethodCallExpression expression, ExpressionContext context, Expression oppsiteExpression)
         {
             this.context = context;
@@ -42,7 +41,17 @@ namespace SqlSugar
 
         public string GetSql()
         {
-            return "";
+            allMethods.Reverse();
+            List<KeyValuePair<string, string>> sqls = new List<KeyValuePair<string, string>>();
+            foreach (var methodExp in allMethods)
+            {
+                var isFirst = allMethods.First() == methodExp;
+                var isLast= allMethods.Last() == methodExp;
+                var sql= SubTools.GetMethodValue(this.context, methodExp.Arguments[0],this.context.IsSingle?ResolveExpressType.WhereSingle:ResolveExpressType.WhereMultiple);
+                sqls.Add(new KeyValuePair<string, string>(methodExp.Method.Name, sql));
+            }
+            var result= this.context.DbMehtods.CaseWhen(sqls);
+            return result;
         }
     }
 }

Src/Asp.Net/SqlSugar/ExpressionsToSql/DbMethods/DefaultDbMethod.cs

@@ -324,5 +324,29 @@ namespace SqlSugar
         {
             return "GETDATE()";
         }
+
+        public virtual string CaseWhen(List<KeyValuePair<string, string>> sqls)
+        {
+            StringBuilder reslut = new StringBuilder();
+            foreach (var item in sqls)
+            {
+                if (item.Key == "IF")
+                {
+                    reslut.AppendFormat(" ( CASE  WHEN {0} ", item.Value);
+                }
+                else if (item.Key == "End")
+                {
+                    reslut.AppendFormat("ELSE {0} END )", item.Value);
+                }
+                else if (item.Key == "Return")
+                {
+                    reslut.AppendFormat(" THEN {0} ", item.Value);
+                }
+                else {
+                    reslut.AppendFormat(" WHEN {0} ", item.Value);
+                }
+            }
+            return reslut.ToString();
+        }
     }
 }

Src/Asp.Net/SqlSugar/ExpressionsToSql/DbMethods/IDbMethods.cs

@@ -36,6 +36,7 @@ namespace SqlSugar
         string ToGuid(MethodCallExpressionModel model);
         string ToDouble(MethodCallExpressionModel model);
         string ToBool(MethodCallExpressionModel model);
+        string CaseWhen(List<KeyValuePair<string,string>> sqls);
         string Substring(MethodCallExpressionModel model);
         string ToDate(MethodCallExpressionModel model);
         string ToTime(MethodCallExpressionModel model);

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

@@ -56,7 +56,16 @@ namespace SqlSugar
                 return;
             }
             else if (IsIfElse(express, methodName)) {
-                List<Expression> expList = new List<Expression>();
+                CaseWhenResolve caseResole = new CaseWhenResolve(express, this.Context, parameter.OppsiteExpression);
+                var appendSql = caseResole.GetSql();
+                if (this.Context.ResolveType.IsIn(ResolveExpressType.SelectMultiple, ResolveExpressType.SelectSingle))
+                {
+                    parameter.BaseParameter.CommonTempData = appendSql;
+                }
+                else
+                {
+                    base.AppendValue(parameter, isLeft, appendSql);
+                }
                 return;
             }
             if (IsContainsArray(express, methodName, isValidNativeMethod))