SQL
Rules for Case-Sensitivity
In case of a conflict, when the same identifier is spelt with different cases, one will be selected randomly. For example:  
```sql
CREATE TABLE t1 (idfield INTEGER, x INTEGER);
CREATE TABLE t2 (IdField INTEGER, y INTEGER);
INSERT INTO t1 VALUES (1, 123);
INSERT INTO t2 VALUES (1, 456);
SELECT * FROM t1 NATURAL JOIN t2;
```  
| idfield |  x  |  y  |
|--------:|----:|----:|
| 1       | 123 | 456 |