Nullables Still Acting Up

[say25]

Try to run copyHelper.SaveAll(connection, entities);

Where entities is a list of Student Objects with a string Name field and nullable int field for age.

If the first student in the entities list has a null age and the second has an age defined, it freaks out and fails.

[bytefish]

Weird. 🤔 I will look into it, but it will take some time. Would you mind writing a small Unit Test to reproduce the problem?

[say25]

Working on that now

[say25]

Without exposing my code too much (working in an Enterprise project), the test should look like this:

        [Test]
        public void Test_NullableSmallInt_FirstNull()
        {

            var entity0 = new TestEntity()
            {
                SmallInt = null
            };

            var entity1 = new TestEntity()
            {
                SmallInt = Int16.MaxValue
            };

            subject.SaveAll(connection, new[] { entity0, entity1 });

            var result = GetAll();

            // Check if we have the amount of rows:
            Assert.AreEqual(2, result.Count);

            Assert.IsNotNull(result[0][0]);
            Assert.IsNotNull(result[1][0]);

            Assert.AreEqual(Int16.MinValue, (Int16)result[0][0]);
            Assert.AreEqual(Int16.MaxValue, (Int16)result[1][0]);
        }

Unfortunately running the test against my RDS actually fails :(

[say25]

This is obviously an example but should apply to all types, Integer, Numeric, etc.

[bytefish]

Thanks! I will investigate it. Honestly I think about rolling everything back to Npgsql 3.2.7. 😥

[say25]

Got it working. I needed to simply run create schema sample; first. but yea these all fail. Let me put in a PR for the tests.

[bytefish]

Looking at the test it has to fail, because of this line:

 Assert.AreEqual(Int16.MinValue, (Int16)result[0][0]);

The result should be null. I am not near a computer, so I cannot look into it. 😌

[say25]

Fails before it gets to that line unfortunately. But yea I will patch that in the PR.

   at Npgsql.NpgsqlParameter`1.ValidateAndGetLength() in C:\projects\npgsql\src\Npgsql\NpgsqlParameter`.cs:line 90
   at Npgsql.NpgsqlBinaryImporter.Write[T](T value, NpgsqlParameter param) in C:\projects\npgsql\src\Npgsql\NpgsqlBinaryImporter.cs:line 244
   at PostgreSQLCopyHelper.PostgreSQLCopyHelper`1.<>c__DisplayClass12_0`1.<MapNullable>b__0(NpgsqlBinaryImporter writer, TEntity entity) in D:\work\projects\PostgreSQLCopyHelper\PostgreSQLCopyHelper\PostgreSQLCopyHelper\PostgreSQLCopyHelper\PostgreSQLCopyHelper.cs:line 61
   at PostgreSQLCopyHelper.PostgreSQLCopyHelper`1.WriteToStream(NpgsqlBinaryImporter writer, IEnumerable`1 entities) in D:\work\projects\PostgreSQLCopyHelper\PostgreSQLCopyHelper\PostgreSQLCopyHelper\PostgreSQLCopyHelper\PostgreSQLCopyHelper.cs:line 74
   at PostgreSQLCopyHelper.PostgreSQLCopyHelper`1.SaveAll(NpgsqlConnection connection, IEnumerable`1 entities) in D:\work\projects\PostgreSQLCopyHelper\PostgreSQLCopyHelper\PostgreSQLCopyHelper\PostgreSQLCopyHelper\PostgreSQLCopyHelper.cs:line 39
   at PostgreSQLCopyHelper.Test.NullableBasicDataTypesTest.Test_NullableSmallInt_NullFirst() in D:\work\projects\PostgreSQLCopyHelper\PostgreSQLCopyHelper\PostgreSQLCopyHelper\PostgreSQLCopyHelper.Test\NullableBasicDataTypesTest.cs:line 76

Here is the stack FYI

[bytefish]

Meanwhile, please stay on Version 1.3.0 until there is a fix in place.

[bytefish]

This is how Nullables are written. Are you able to spot an obvious error there?

• https://github.com/bytefish/PostgreSQLCopyHelper/blob/4ecb2aa0bdfc7042838eb902223e096bd1b641a1/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.cs#L52

[say25]

I looked there first. It should basically use the writer.Write(DBNull.Value, type); the first time and then writer.Write(value, type); the second time. Looks like it should work but... :/

[bytefish]

The Npgsql Binary writer has a WriteNull() method. Could you try if replacing this with my current DBNull.Value writing fixes the issue?

[say25]

That does fix the issue 😎

[bytefish]

💪💪💪

I will fix it and release a new version to NuGet. Thanks for your help!

[say25]

No problem thanks for your responsiveness :D

[bytefish]

I have released a new Version 2.2.0 to NuGet, which should fix the issue. If the problem still persists, please reopen the ticket. And thanks again! 👍

[bytefish]

Sorry I was too quick to close! I will add your tests later today in a separate merge.