Sql update from select

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Problem

A SQL UPDATE query is used to alter, add, or remove data within some or all tuples in existing rows of a table.

In the typical format, we usually update one tuple at a time in a table. We can also update multiple tuples at a time when we make use of the WHERE clause.

Databricks update with join

Alternatively, we can update all the tuples in a column with a simple UPDATE statement. However, in the later scenario, all the rows will have the same value in that column. Now, what if you want to update all the tuples in one or more columns of a table with unique corresponding values in another table.

Our simple UPDATE TABLE NAME SET COLUMN NAMES statement will not work in this scenario. Okay, actually it will, but it would be a long tedious script when you are working with a few hundred or a few thousand rows of data.

Solution

In this tutorial, we will explore three options that will update all the tuples in one or more columns with unique values that are stored in a separate table.

In the first option, we will use the JOIN as a form of a SELECT statement and

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