课程: SQL Server Fundamentals: Master Basic Query Techniques

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Relational database concepts

Relational database concepts

课程: SQL Server Fundamentals: Master Basic Query Techniques

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Relational database concepts

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- [Instructor] At first glance, it might look like the tables in a relational database would be structured in pretty much the same way as tables that you might be used to in other contexts, from Excel files or a table in a textbook. There are some key differences however, which we'll cover in this video. We're going to start With a simple sample dataset to demonstrate how relational databases organize information. This order's table looks like something you might see in an Excel file with information about customers, where they live, what they purchased, how much each item costs and the order total. Looking at this dataset, you might notice some inefficiencies in storing the data this way, because we are recording some of the same data points over and over, such as the customer's location or the price of a bottle of oil versus a case of oil. We also have multiple rows for the same order when more than one type of item…

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