Handle NULL reference error on clone

Author: ahmad-moussawi

QueryBuilder.Tests/ExecutionTests.cs

@@ -23,5 +23,14 @@ public void TimeoutShouldBeCarriedToNewCreatedFactory()
             var newFactory = QueryExtensions.CreateQueryFactory(db.Query());
             Assert.Equal(db.QueryTimeout, newFactory.QueryTimeout);
         }
+        
+        [Fact(Skip = "timeout over cloned xQuery is not supported yet")]
+        public void TimeoutShouldBeCarriedToNewCreatedFactoryAfterClone()
+        {
+            var db = new QueryFactory();
+            db.QueryTimeout = 4000;
+            var newFactory = QueryExtensions.CreateQueryFactory(db.Query().Clone());
+            Assert.Equal(db.QueryTimeout, newFactory.QueryTimeout);
+        }
     }
 }

QueryBuilder.Tests/MySqlExecutionTest.cs

@@ -54,6 +54,71 @@ Color TEXT NULL
 
             db.Statement("DROP TABLE IF EXISTS `Cars`");
         }
+
+        [Fact]
+        public void Count()
+        {
+            var db = SetupDb();
+            var sql = @"
+                CREATE TABLE Cars(
+                    Id INT PRIMARY KEY AUTO_INCREMENT,
+                    Brand TEXT NOT NULL,
+                    Year INT NOT NULL,
+                    Color TEXT NULL
+                )
+            ";
+            db.Statement(sql);
+
+            db.Statement("INSERT INTO `Cars`(Brand, Year) VALUES ('Honda', 2020)");
+            var count = db.Query("Cars").Count<int>();
+            Assert.Equal(1, count);
+
+            db.Statement("INSERT INTO `Cars`(Brand, Year) VALUES ('Toyota', 2021)");
+            count = db.Query("Cars").Count<int>();
+            Assert.Equal(2, count);
+
+            int affected = db.Query("Cars").Delete();
+            Assert.Equal(2, affected);
+
+            count = db.Query("Cars").Count<int>();
+            Assert.Equal(0, count);
+
+            db.Statement("DROP TABLE IF EXISTS `Cars`");
+        }
+
+        [Fact]
+        public void CloneThenCount()
+        {
+            var db = SetupDb();
+            var sql = @"
+                CREATE TABLE Cars(
+                    Id INT PRIMARY KEY AUTO_INCREMENT,
+                    Brand TEXT NOT NULL,
+                    Year INT NOT NULL,
+                    Color TEXT NULL
+                )
+            ";
+            db.Statement(sql);
+
+            for (int i = 0; i < 10; i++)
+            {
+                db.Query("Cars").Insert(new
+                {
+                    Brand = "Brand " + i,
+                    Year = "2020",
+                });
+            }
+
+            var query = db.Query("Cars").Where("Id", "<", 5);
+            var count = query.Count<int>();
+            var cloneCount = query.Clone().Count<int>();
+
+            Assert.Equal(4, count);
+            Assert.Equal(4, cloneCount);
+
+            db.Statement("DROP TABLE IF EXISTS `Cars`");
+        }
+
         public QueryFactory SetupDb()
         {
             var host = System.Environment.GetEnvironmentVariable("SQLKATA_MYSQL_HOST");

SqlKata.Execution/Query.Extensions.cs

@@ -366,7 +366,16 @@ internal static XQuery CastToXQuery(Query query, string method = null)
 
         internal static QueryFactory CreateQueryFactory(XQuery xQuery)
         {
-            var factory = new QueryFactory(xQuery.Connection, xQuery.Compiler, xQuery.QueryFactory.QueryTimeout);
+            QueryFactory factory;
+
+            if (xQuery.QueryFactory != null)
+            {
+                factory = new QueryFactory(xQuery.Connection, xQuery.Compiler, xQuery.QueryFactory.QueryTimeout);
+            }
+            else
+            {
+                factory = new QueryFactory(xQuery.Connection, xQuery.Compiler);
+            }
 
             factory.Logger = xQuery.Logger;
 

SqlKata.Execution/XQuery.cs

@@ -14,14 +14,20 @@ public class XQuery : Query
 
         public XQuery(IDbConnection connection, Compiler compiler)
         {
+            this.QueryFactory = new QueryFactory(connection, compiler);
             this.Connection = connection;
             this.Compiler = compiler;
         }
 
         public override Query Clone()
         {
 
-            var query = new XQuery(this.Connection, this.Compiler);
+            var query = new XQuery(this.QueryFactory.Connection, this.QueryFactory.Compiler);
+
+            if (this.QueryFactory?.QueryTimeout != null)
+            {
+                query.QueryFactory.QueryTimeout = this.QueryFactory?.QueryTimeout ?? 30;
+            }
 
             query.Clauses = this.Clauses.Select(x => x.Clone()).ToList();
             query.Logger = this.Logger;