Create advanced connections for MySQL

Source: Internet
Author: User

Create advanced connections for MySQL

SQL allows an alias for a table. The two main reasons for doing so are:

The SQL statement can be shortened; the same table can be used multiple times in a single SELECT statement; the alias is used to represent a table corresponding to the previous one:

Auto join

Problem: If you know that the ID of a product produced by a vendor is DTNTR, you need to find out all other products produced by the vendor from the database.

The following SELECT statement can be used to find all products produced by the vend_id:

Now let's look at the same query using the join:

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