BitArray: bit string length 1 does not match type bit(256)

[zezba9000]

Created a postgresql tabel on my local computer with 2 columns (SystemID [as uuid], TrackingIDs [as Bit[] with size 256]).

In C# ASP.NET I'm getting the error:

22026: bit string length 1 does not match type bit(256)

"new BitArray(256)" is 256 in length not '1' as the error suggests.

Here is an example of my C# code:

using (var connection = new NpgsqlConnection(DBUtils.connectionString))
{
    try
    {
        connection.Open();
        using (var cmd = connection.CreateCommand())
        {
            cmd.CommandText = "INSERT INTO hosts VALUES(@SystemID, @TrackingIDs)";
            cmd.Parameters.AddWithValue("@SystemID", NpgsqlDbType.Uuid, systemID);
            cmd.Parameters.AddWithValue("@TrackingIDs", NpgsqlDbType.Bit | NpgsqlDbType.Array, new BitArray(256));
            return cmd.ExecuteNonQuery() != 0 ? "Success" : "Failed";
        }
    }
    catch (Exception ex)
    {
        return ex.Message;
    }
    finally
    {
        connection.Close();
    }
}

Further technical details

pgAdmin4: 3.6
Npgsql version: 4.0.4
PostgreSQL version: 11.1
Operating system: Win10 x64
ASP.NET: .NET Core 2.2

[austindrenski]

Per the previous thread:

Manually setting the size to 256 and its thinking its 1 in length?

What exactly are you trying to do by setting the size explicitly?

Consider the following sample which completes successfully:

static void Main(string[] args)
{
    var connection = $"Host=localhost;Port=5432;Username={args[0]};Password={args[1]};";

    using (var conn = new NpgsqlConnection(connection))
    {
        conn.Open();

        using (var cmd = conn.CreateCommand())
        {
            cmd.CommandText = "CREATE TEMP TABLE some_table( some_column bit[] );";
            cmd.ExecuteNonQuery();
        }

        using (var cmd = conn.CreateCommand())
        {
            cmd.CommandText = "INSERT INTO some_table VALUES( @p )";
            cmd.Parameters.AddWithValue("@p", NpgsqlDbType.Bit | NpgsqlDbType.Array, new BitArray(256));
            cmd.ExecuteNonQuery();
        }
    }

    Console.WriteLine("Completed successfully");
}

some_database=# \d some_table;
              Table "pg_temp_4.some_table"
   Column    |   Type   | Collation | Nullable | Default
-------------+----------+-----------+----------+---------
 some_column | bit(1)[] |           |          |

[zezba9000]

O ic. "bit(8)[2]" would equal two bytes. I was thinking bit(8) was the same thing as bit[8] as in bit always meant a single bit as in a bit from a byte for example. Bit in this case can be any dimension for postgresql.

So guess I'm looking to create a fixed size of bit(1)[256] in length. Which means I create a single bit and set its length to 256 in postgresql terms?

[zezba9000]

Yep that was it. Ok sorry for the confusion. Was just doing stuff in MySQL which is a lot more limited. PostgreSQL is awesome it divides stuff up like this.

[austindrenski]

Yep that was it. Ok sorry for the confusion. Was just doing stuff in MySQL which is a lot more limited. PostgreSQL is awesome it divides stuff up like this.

No worries! I actually misread your error message to be bit[256] instead of bit(256), so apologies if that sample was a bit off base.

Glad that we were able to get to the bottom of it. Feel free to post back here if you encounter any other issues with this topic.

[austindrenski]

P.S. I've opened #2270 to track updating the docs with a sample or two based on this thread.