Microsoft sql inner join examples

The book titles are stored in the books table, and the author names are stored in the authors table. In the FROM clause, we specify the first table to join also referred to as the left table. Then, we use the ON keyword to tell the database which columns should be used for matching the records i. Note also that we are using aliases for table names i.

The table aliases reduce typing and make the query more readable. For each record in the left table i. It then pulls the corresponding first name and last name. In our example, all books have a corresponding author and all authors have at least one corresponding book. Only half of our books have been translated and thus have a corresponding translator. The query outputs only those books that have been translated. Now we know how to join tables when we need only the matched records to be displayed.

But, what if we want to keep all of the books in the resulting set without cutting the table to the translated books only? You should apply this SQL JOIN type when you want to keep all records from the left table and only the matched records from the right table. We also want to keep the basic information about each book i. See that we start with the books table in the FROM clause, making it the left table. Note the NULL values in the translator column. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.

Feedback will be sent to Microsoft: By pressing the submit button, your feedback will be used to improve Microsoft products and services. Privacy policy. The names of the fields that are joined.

If they are not numeric, the fields must be of the same data type and contain the same kind of data, but they do not have to have the same name. Your message has been sent to W3Schools. W3Schools is optimized for learning and training. Examples might be simplified to improve reading and learning. Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content. If a row is matched, it is included in the final result set.

Suppose the columns in the A and B tables are a and b. The following statement illustrates the inner join clause:. The condition to match between table A and table B is specified after the ON keyword. This condition is called join condition i.