Error when inserting triples in MySQL (on 1.1)

[Olivier Berger]

The following commit fixes missing string casts for model's URI when using MySQL backend in 1.1 : olberger@2c1eda9

[Konrad Abicht]

Hi,
thanks for participation! Please, could you make a pull request that we can handle this commit properly?

Best,
K

[Olivier Berger]

Sent.

Best regards,