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Schema validation

Schema validation - SQL教程

课程: SQL for Testers

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Schema validation

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- [Instructor] You might have heard about database schemas before, but what are they? Well, essentially it's the layout and structure of all the data in your database. In our sample application, we've got a few different tables and you've probably noticed that they're connected to each other in various ways. The schema is what defines the structure and the connections between all the data in those tables in our database. That's all a little abstract, so let's draw it out. I have a picture here with the four tables in our system. So part of a schema is just laying out these tables with the various columns in them, and that's what I've done here. I've got these four tables. I've got the list of columns that is in each of those tables. But we know that there's some relationships between these tables. So the category ID here is linked to the category ID in the products table. And the cart is also linked to the other table, so the cart user ID is linked to the user's table, and the product…

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