How to use dynamic values while executing SQL scripts in R

Question

My R workflow now involves dealing with a lot of queries (RPostgreSQL library). I really want to make code easy to maintain and manage in the future.

I

Answer 1

sqlInterpolate() is for substituting values only, not other components like table names. You could use other templating frameworks such as brew or whisker.

Answer 2

In ?DBI::SQL, you can read:

By default, any user supplied input to a query should be escaped using either dbQuoteIdentifier() or dbQuoteString() depending on whether it refers to a table or variable name, or is a literal string.

Also, on this page:

You may also need dbQuoteIdentifier() if you are creating tables or relying on user input to choose which column to filter on.

So you can use:

sqlInterpolate(ANSI(), 
               "SELECT count(*) FROM ?my_table", 
               my_table = dbQuoteIdentifier(ANSI(), "table_name"))
# <SQL> SELECT count(*) FROM "table_name"