Bug #88058 DECIMAL with NumericScale of 0 has wrong NumericPrecision in GetSchemaTable
Submitted: 11 Oct 2017 12:50 Modified: 8 Jan 2018 21:47
Reporter: Bradley Grainger (OCA) Email Updates:
Status: Closed Impact on me:
None 
Category:Connector / NET Severity:S3 (Non-critical)
Version:6.9.9 OS:Windows (10.0.15063 x64)
Assigned to: CPU Architecture:Any

[11 Oct 2017 12:50] Bradley Grainger 
Description:
When a decimal column is defined with a scale of 0 (e.g., DECIMAL(8, 0)), the "NumericPrecision" value returned by GetSchemaTable is off by one.

How to repeat:
Execute the following SQL:
	create schema schema_table collate utf8_bin;
	create table schema_table.datatypes(
		decimal0 decimal(8, 0)
	);

Then run this C# code:
	using (var connection = new MySqlConnection("..."))
	{
		connection.Open();
		
		using (var cmd = connection.CreateCommand())
		{
			cmd.CommandText = "SELECT * FROM schema_table.datatypes;";
			using (var reader = cmd.ExecuteReader())
			{
				var schemaTable = reader.GetSchemaTable();
				Console.WriteLine(schemaTable.Rows[0]["NumericPrecision"]); // prints 7, expected 8
			}
		}
	}

Suggested fix:
At https://github.com/mysql/mysql-connector-net/blob/5864e6b21a8b32f5154b53d1610278abb3cb1cee..., if field.Scale==0, add one to field.Precision for the omitted decimal point.
[11 Oct 2017 13:34] Chiranjeevi Battula 
Hello Bradley Grainger,

Thank you for the bug report and test case.
Verified this behavior on Visual Studio 2013 (C#.Net) and Connector/NET 6.9.9 version.

Thanks,
Chiranjeevi.
[11 Oct 2017 13:34] Chiranjeevi Battula 
Screenshot

Attachment: 88058.JPG (image/jpeg, text), 151.49 KiB.
[8 Jan 2018 21:47] Christine Cole 
Posted by developer:
 
Fixed as of the upcoming MySQL Connector/NET 6.9.11 release, and here's the changelog entry:

When a decimal column was defined with a scale of zero, such as DECIMAL(8,
0), the value of the NumericPrecision field returned by the
MySqlDataReader.GetSchemaTable method was lower by one. For example, it
returned 7 instead of 8 as expected.

Thank you for the bug report.