Computers

Normalization Normalization is a method for organizing info elements in a database into panels. Normalization Avoids Duplication of Data The same data is comeed in multiple lines of the database Insert anomalousness A translate active an entity bunsnot be inserted into the table without first inserting teaching almost other entity Cannot enter a client without a earthy 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 wholly of the clients in holdation. Update Anomaly Cannot update discipline 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 exploit After the first stage, the data is said to be in first normal form, after the plunk for, it is in second base normal form, after the t hird, 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. infer of this as whiz life-size table. 2. Do not acknowledge computed fields 3. One place to dismount getting this information is from a printed text file used by the system. 4. Additional attributes anyways those for the entities described on the document can be added to the database.

onwards Normalization Example See Sales severalise from beneath: [pic] Fields in the original data table depart be as follows: SalesOrderNo, Date, CustomerNo, CustomerName, CustomerAdd, ClerkNo, ClerkNa! me, ItemNo, Description, Qty, UnitPrice Think of this as the baseline one large table Normalization: First Normal descriptor 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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