RMLTC0018a-MySQL: space-padding of CHAR(15) columns is autoremoved in MySQL

[thomas-delva]

The test case uses a column with type CHAR(15) containing values shorter than 15 characters, such as 'Venus'. The expected output contains literals of length 15, with spaces added, e.g., "Venus ". (Unfortunately github markdown renders this with 1 trailing space, but there should be 10.)

However, MySQL autoremoves these trailing spaces, so the mapper generates values like "Venus", leading to a test failure.

If MySQL treats a CHAR(15) with trailing spaces like a short string without spaces, I think the literal should also be this short string since that's a faithful representation of the database value. (This is up for discussion.) Also, I did not find anything in the part of the R2RML spec mentioned in the test case description (or in other parts of the spec) about adding space-padding to short CHAR(15)s.

[thomas-delva]

I have not looked at the behaviour of other databases (postgres, sqlserver) for fixed-length character arrays yet. Will do so when I go over their test cases.

[thomas-delva]

The same test case for PostgreSQL (RMLTC0018a-PostgreSQL) does create padded literals