Tuesday, October 8, 2019
The Art of Analysis Research Paper Example | Topics and Well Written Essays - 250 words
The Art of Analysis - Research Paper Example Dependencies should not be partial on the combined key; this is the main task in this stage. The items in the table must depend on all the combined keys, attributes should not depend on only one of the keys. Sending of normal form fails if this is not attained. Item total price and order total price are derivatives, hence, they should not be a part of the database all these fields, apart from the item quantity, do not fully depend on both order id and item id, hence, the table fails the 2nd normal form standards or requirements. The solution to this is to split the table into two tables so that the items that depend on order id fall in the table with order-id as the primary key, while those items that depend on item-id fall in that table too. Given that item_qty fully depends on order id, item id field and order id field, which is also in the order-item table as primary forming a many to one relation indicated in the diagrams. After this, the table now passed to the 2nd normal form by having field which depends fully on the primary key in the orders table (Diagram 3) but in order-items table the item_price and item_descripition do not depend on order_id as in case with the primary key, hence, further splitting of this table is needed. With diagram 4 all the requirements for the 2nd normalization have been achieved.
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