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Fix typo (#1039) 

it said 'dplyr' where it should have been 'dbplyr'
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fellennert 2022-06-03 19:11:25 +02:00 committed by GitHub
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import-databases.qmd
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@ -453,7 +453,7 @@ Notice how `desc()` is translated to `DESC`: this is one of the many dplyr funct
Sometimes it's not possible to translate a dplyr pipeline into a single `SELECT` statement and you need to use a subquery. Sometimes it's not possible to translate a dplyr pipeline into a single `SELECT` statement and you need to use a subquery.
A **subquery** is just a query used as a data source in the `FROM` clause, instead of the usual table. A **subquery** is just a query used as a data source in the `FROM` clause, instead of the usual table.
dplyr typically uses subqueries to work around limitations of SQL. dbplyr typically uses subqueries to work around limitations of SQL.
For example, expressions in the `SELECT` clause can't refer to columns that were just created. For example, expressions in the `SELECT` clause can't refer to columns that were just created.
That means that the following (silly) dplyr pipeline needs to happen in two steps: the first (inner) query computes `year1` and then the second (outer) query can compute `year2`. That means that the following (silly) dplyr pipeline needs to happen in two steps: the first (inner) query computes `year1` and then the second (outer) query can compute `year2`.