SNOW-1917622 Fix passing null into a query parameter (#1112)

Co-authored-by: VelvetAndrea <[email protected]>

Author: sfc-gh-knozderko

Snowflake.Data.Tests/IntegrationTests/SFBindTestIT.cs

@@ -63,7 +63,8 @@ public void TestArrayBind()
         }
 
         [Test]
-        public void TestBindNullValue()
+        [TestCaseSource(nameof(NullTestCases))]
+        public void TestBindNullValue(object nullValue)
         {
             using (SnowflakeDbConnection dbConnection = new SnowflakeDbConnection())
             {
@@ -154,7 +155,7 @@ public void TestBindNullValue()
                         if (isTypeSupported)
                         {
                             command.CommandText = $"insert into {TableName}({colName}) values(:p0)";
-                            param.Value = DBNull.Value;
+                            param.Value = nullValue;
                             command.Parameters.Add(param);
                             int rowsInserted = command.ExecuteNonQuery();
                             Assert.AreEqual(1, rowsInserted);
@@ -164,7 +165,7 @@ public void TestBindNullValue()
                             try
                             {
                                 command.CommandText = $"insert into {TableName}(stringData) values(:p0)";
-                                param.Value = DBNull.Value;
+                                param.Value = nullValue;
                                 command.Parameters.Add(param);
                                 int rowsInserted = command.ExecuteNonQuery();
                             }
@@ -199,6 +200,9 @@ public void TestBindNullValue()
             }
         }
 
+        private static IEnumerable<object> NullTestCases() =>
+            new object[] { DBNull.Value, null };
+
         [Test]
         public void TestBindValue()
         {

Snowflake.Data/Client/SnowflakeDbCommand.cs

@@ -375,6 +375,11 @@ private static Dictionary<string, BindingDTO> convertToBindList(List<SnowflakeDb
                     string bindingType = "";
                     object bindingVal;
 
+                    if (parameter.Value == null)
+                    {
+                        parameter.Value = DBNull.Value;
+                    }
+
                     if (parameter.Value.GetType().IsArray &&
                         // byte array and char array will not be treated as array binding
                         parameter.Value.GetType().GetElementType() != typeof(char) &&