¿Podemos unir dos tablas con relación de clave externa primaria?

Can we join two tables with primary foreign key relation?

A primary key is not required. A foreign key is not required either. You can construct a query joining two tables on any column you wish as long as the datatypes either match or are converted to match. No relationship needs to explicitly exist.

Using SQL Server Management Studio

1. In Object Explorer, right-click the table that will be on the foreign-key side of the relationship and click Design.
2. From the Table Designer menu, click Relationships.
3. In the Foreign-key Relationships dialog box, click Add.
4. Click the relationship in the Selected Relationship list.

Hover your pointer over the table you would like to merge until the table’s handle (the plus sign) appears at its top left corner. You can click and drag the table using that handle. When you release your mouse button, Word merges the two tables.

The order you join won’t break it but depending on which sql product you’re using may effect performance. You need to decide if you want ALL records from both/either table or only records which have a matching mapping entry, this will change the type of join you need to use.

To query data from multiple tables you use join statements. SQL provides several types of joins such as inner join, outer joins (left outer join or left join, right outer join or right join, and full outer join) and self join. In this tutorial, we will show you how to use the INNER JOIN clause. SQL INNER JOIN syntax

We can get the joined data from both tables by running the following query: Try for yourself to JOIN the tracks and albums tables. We can even join all 3 tables together if we’d like using multiple JOIN commands

To fetch data relevant to the customer requirement we might need to join tables which will be fulfilled by joins. As mentioned earlier joins are used to get data from more than one table. To join more than one table we need at least one column common in both tables. Tables get joined based on the condition specified.