SQL challenge
| dept_no | emp_no |
| d001 | 110022 |
| d001 | 110039 |
| d002 | 110085 |
| d002 | 110114 |
| d003 | 110183 |
| d003 | 110228 |
| d004 | 110303 |
| d004 | 110344 |
| d004 | 110386 |
| d004 | 110420 |
| d005 | 110511 |
| d005 | 110567 |
| d006 | 110725 |
| d006 | 110765 |
| d006 | 110800 |
| d006 | 110854 |
| d007 | 111035 |
| d007 | 111133 |
| d008 | 111400 |
| d008 | 111534 |
| d009 | 111692 |
| d009 | 111784 |
| d009 | 111877 |
| d009 | 111939 |