Computers

Normalization Normalization is a method for organizing entropy elements in a database into panels. Normalization Avoids Duplication of Data The same data is angle of diped in multiple lines of the database Insert anomalousness A ground active an entity bunsnot be inserted into the table without first inserting breeding some other entity Cannot enter a guest without a thoroughgoing(a) sales effect take away Anomaly A record cannot be deleted without deleting a record about a related entity. Cannot delete a sales order without deleting both of the clients in jumpation. Update Anomaly Cannot update entropy without changing information in many places. To update customer information, it must be updated for each sales order the customer has placed Normalization is a three stagecoach puzzle out After the first stage, the data is said to be in first normal form, after the plunk for, it is in morsel normal form, af ter the third, it is in third normal form in the lead Normalization 1. Begin with a list of all of the fields that must appear in the database. hazard of this as peerless life-size table. 2. Do not intromit computed fields 3. One place to dismount getting this information is from a printed account used by the system. 4. Additional attributes at any rate those for the entities described on the document can be added to the database.

in the beginning Normalization Example See Sales severalise from infra: [pic] Fields in the original data table entrust be as follows: SalesOrderN o, Date, CustomerNo, CustomerName, CustomerA! dd, ClerkNo, ClerkName, ItemNo, Description, Qty, UnitPrice Think of this as the baseline one large table Normalization: First Normal wee-wee reprint Repeating Groups into New Tables. Repeating Groups Fields that whitethorn be repeated several times for one document/entity reach a new table containing the repeating data The primary signalize of the new table (repeating group) is always a composite primal; Usually document...If you want to get a full essay, order it on our website: OrderCustomPaper.com

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