Sql update outer join oracle

This is a guide to Oracle Update with Join. Here we discuss the definition, syntax, and How update with join works in Oracle? You may also have a look at the following articles to learn more —. Submit Next Question. By signing up, you agree to our Terms of Use and Privacy Policy. Forgot Password? This website or its third-party tools use cookies, which are necessary to its functioning and required to achieve the purposes illustrated in the cookie policy.

By closing this banner, scrolling this page, clicking a link or continuing to browse otherwise, you agree to our Privacy Policy. Oracle Update with Join. Popular Course in this category. Course Price View Course. To perform a self join, Oracle Database combines and returns rows of the table that satisfy the join condition. If two tables in a join query have no join condition, then Oracle Database returns their Cartesian product. Oracle combines each row of one table with each row of the other.

A Cartesian product always generates many rows and is rarely useful. For example, the Cartesian product of two tables, each with rows, has 10, rows. Always include a join condition unless you specifically need a Cartesian product. If a query joins three or more tables and you do not specify a join condition for a specific pair, then the optimizer may choose a join order that avoids producing an intermediate Cartesian product.

An inner join sometimes called a simple join is a join of two or more tables that returns only those rows that satisfy the join condition.

An outer join extends the result of a simple join. An outer join returns all rows that satisfy the join condition and also returns some or all of those rows from one table for which no rows from the other satisfy the join condition. For all rows in A that have no matching rows in B, Oracle Database returns null for any select list expressions containing columns of B. For all rows in B that have no matching rows in A, Oracle returns null for any select list expressions containing columns of A.

You can use outer joins to fill gaps in sparse data. Sparse data is data that does not have rows for all possible values of a dimension such as time or department. For example, tables of sales data typically do not have rows for products that had no sales on a given date.

Filling data gaps is useful in situations where data sparsity complicates analytic computation or where some data might be missed if the sparse data is queried directly. But I get how this works now Any difference in between will be set to null. Patrick Bacon Patrick Bacon 4, 1 1 gold badge 24 24 silver badges 31 31 bronze badges.

Thanks, I started exploring this path shortly after I posted and this will definitely work as well though not quite as efficient.

Appreciate the post! Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Making Agile work for data science. Stack Gives Back Featured on Meta. New post summary designs on greatest hits now, everywhere else eventually.