A database table, SALES, is used to keep a record of items made and sold by a furniture maker. Item number | Order number | Notes | Amount | Status ---|---|---|---|--- CH001 | 1921 | Smith – six dining chairs | 6 | Delivered TB003 | 1921 | Smith – large table | 1 | In progress CH001 | 1924 | Hue – extra chairs | 4 | In progress CH003 | 1925 | For stock | 2 | Cancelled BN001 | 1927 | Patel – replacement bench | 1 | Not started ST002 | 1931 | Sola – small table | 1 | Delivered CH003 | 1927 | Patel – eight dining chairs with arms | 8 | Not started TB003 | 1927 | Patel – large table | 1 | Not started

1. (a)Explain why the field Item number could not be used as a primary key.[1]
2. (b)A query-by-example has been written to display only the order number and item numbers of any items in progress or not started. Field: | Item number | Order number | Amount | Status ---|---|---|---|--- Table: | SALES | SALES | SALES | SALES Sort: | | | | Show: | [ ] | [✓] | [✓] | [ ] Criteria: | | | | Not Like "Delivered" or: | | | | Explain why the query-by-example is incorrect, and write a correct query-by-example. Explanation Field: | Item number | Order number | Amount | Status ---|---|---|---|--- Table: | | | | Sort: | | | | Show: | | | | Criteria: | | | | or: | | | | [5]