Data model review and SQL primer using Northwinds and online SQL tutorial

Data model review - MIS 235 Database Model SQL Review This tutorial is designed to develop basic skills in querying data from a relational database

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MIS 235 This tutorial is designed to develop basic skills in querying data from a relational database using Structured Query Language (SQL). The data model for the Northwinds company database is pictured below. It illustrates the structure of the database. Each box represents a table and contains a list of the attributes stored in that table. The boldfaced attribute (or attributes) in each table are the unique identifiers for each row in the table. For example the ProductID uniquely identifies each product. These are also known as primary keys. Northwinds Data Model The lines in the illustration depict relationships in the data. The cardinality of the relationships is labeled with a one and an infinity symbol, representing the one and many sides of the relationship. This is where relational databases get their name. Related information in multiple tables is connected by storing the primary key of one table as a foreign key in another. Relationships can be one to one, one to many, or many to many. In this database all relationships are one to many. For example the relationship between customers and orders is… A customer can place many orders and an order is placed by only one customer . The relationship between Suppliers and Products can be interpreted as each supplier provides many products and each product is supplied by one Supplier . The lines in the data model point to the foreign key fields in the many side of the relationship. Being able to read data base documentation and knowing keys and relationships is important to understanding and accessing the information stored in a relational database. Querying the data is impossible without an understanding the data in the database.
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SQL REVIEW MATERIAL There are several resources saved on the G: drive for your use. The website below is a “live” tutorial that you can practice your queries on. Try to work through lessons/courses 1 through 10 including all of the review exercises if you need practice. The data model and the tables used in the tutorial are included below for your
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This note was uploaded on 02/13/2012 for the course MIS 235 taught by Professor Sunrro during the Fall '08 term at Miami University.

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Data model review - MIS 235 Database Model SQL Review This tutorial is designed to develop basic skills in querying data from a relational database

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