Thomas J. Taylor

### Description Using the same Rdb2RdfTest dg0016 from #558 Using MySQL 5. There seems to be a problem converting the `VARBINARY` column to `hexBinary`. Instead of base64-encoding the binary data...

Rdb2RdfTest dg0016 Failure: SQL Query Syntax - Illegal Mix of Collation for UNION - TIMESTAMP

2

### Description Running Ontop against Rdb2Rdf Test dg0016 (direct mapping) on MySQL with `'utf8_unicode_ci'` collation results in `SQLException: Illegal mix of collations for operation 'UNION'`. * Test Case: https://github.com/ontop/ontop/tree/version4/test/rdb2rdf-compliance/src/test/resources/D016 *...

OntopVirtualRepository fails to initialize for Direct Mapping of Table or View with No Primary Key

1

### Description May be similar to #395 (Ontop bootstrap generate mapping without primary keys). I have a database that has Tables/Views without a primary key. [MySQL CREATE TABLE](#MySQL+CREATE+TABLE) #### MySQL...

SPARQL Query Transformation to SQL for N-columns results in N-1 Self Joins or Left Joins, Extremely Slow Query Performance

8

### Description I have a Microsoft SQL Server table with 117 columns - 2 key columns. As I add more columns, Ontop adds self-joins for each non-key column, resulting in...

Ensure current application not set when there is no previous current application.

2

Fixes issue #1317 in 2.4 - applies #1318 (merged in 2.3) to 2.4. _We have been running this patch with restlet 2.4.3 for the last 2 years._