rails scope where not
To use the where.not
method in Ruby on Rails, follow these steps:
Step 1: Understand the Purpose of where.not
The where.not
method is used to retrieve records from a database table that do not meet certain conditions. It is the opposite of the where
method, which retrieves records that do meet specified conditions.
Step 2: Access the Model
To use where.not
, you need to access the model for the table you want to query. In Rails, models are typically stored in the app/models
directory.
Step 3: Write the Query
In the model file, you can define a scope or write a custom query using the where.not
method. The syntax for where.not
is as follows:
ModelName.where.not(column_name: value)
You can specify multiple conditions by chaining where.not
calls together.
Step 4: Test the Query
To test the query, you can use the Rails console (rails console
) or write unit tests that exercise the query.
Step 5: Retrieve the Records
Once you have written and tested the query, you can call it from your application code to retrieve the records that match the specified conditions.
That's it! You have now learned the steps to use the where.not
method in Ruby on Rails.