expect_sql function

Detect if a specific SQL statement is sent

Description

expect_sql(object, regexp = NULL, ...)

Arguments

• object: the expression to evaluate
• regexp: the statement to match
• ...: arguments passed to testthat::expect_error()

Details

Sometimes all you need to check is if a specific SQL statement has been sent and you don't care about retrieving the results.

This works by raising an error that contains the statement that is sent to the database as well as the location of the result. Currently, expect_sql() only works with DBI::dbSendQuery() (and most implementations of DBI::dbGetQuery()

which call DBI::dbSendQuery() internally).

Note: this function is experimental and will likely evolve over time. Please be prepared that new releases might break backwards compatibility.

Examples

if (check_for_pkg("RSQLite", message)) {
  with_mock_db({
    con <- dbConnect(RSQLite::SQLite(), dbname = "not_a_db")

    expect_sql(
      dbGetQuery(con, "SELECT carrier, name FROM airlines LIMIT 3"),
      "SELECT carrier, name FROM airlines LIMIT 3"
    )
  })
}