Previously, when writing an ActiveRecord select and wanted to add columns from anything outside of the model you originated from, you'd have to provide a SQL fragment string like so:
Customer.joins(:orders).select("customers.name, orders.total") => SELECT customers.name, orders.total FROM "customers" INNER JOIN "orders" ON "orders"."customer_id" = "customers"."id"
Notice above how we declare columns from the
customers table and the
As of Rails 7.1, you can now stay in the ActiveRecord DSL and provide hash key/values. The query example above can directly be expressed as:
Customer.joins(:orders).select(customers: [:name], orders: [:total]) => SELECT "customers"."name", "orders"."total" FROM "customers" INNER JOIN "orders" ON "orders"."customer_id" = "customers"."id"
You provide the table names as keys and the column names you want to select as Symbols in an Array.
Also, notice that the selected columns in the query are appropriately quoted vs the SQL fragment above.Tweet