How to query with filters in Supabase?

 

Step 1: Set up your Supabase Account and Project

 

1. Create a Supabase account by visiting the Supabase website.
2. Once logged in, create a new project by clicking on "New Project".
3. Enter the project details and click "Create Project". This will set up a new instance for you.

 

Step 2: Install Supabase Client

 

To query data from Supabase, you'll need to install the Supabase JavaScript client in your project.

First, make sure you have Node.js installed. Then, initialize a new Node.js project, if you haven't already:

npm init -y

Next, install the Supabase client library:

npm install @supabase/supabase-js

 

Step 3: Initialize the Supabase Client

 

After installation, you need to initialize the Supabase client using the URL and the public API key of your Supabase project.

const { createClient } = require('@supabase/supabase-js')

const supabaseUrl = 'https://xyzcompany.supabase.co'
const supabaseKey = 'public-anon-key'
const supabase = createClient(supabaseUrl, supabaseKey)

Replace 'https://xyzcompany.supabase.co' and 'public-anon-key' with your actual Supabase project URL and anonymous key found in your project's settings under "API".

 

Step 4: Query with Filters

 

Now, let's retrieve data with specific filters. Assume you have a table named customers.

To fetch all entries from the customers table:

async function getCustomers() {
  let { data, error } = await supabase
    .from('customers')
    .select('*')

  if (error) console.log('Error:', error)
  else console.log('Data:', data)
}

getCustomers()

To filter the customers where the age is greater than 30:

async function getCustomersAgeOver30() {
  let { data, error } = await supabase
    .from('customers')
    .select('*')
    .gt('age', 30)

  if (error) console.log('Error:', error)
  else console.log('Data:', data)
}

getCustomersAgeOver30()

 

Step 5: Use Additional Filter Options

 

Supabase provides various methods for filtering data. Some commonly used filters are:

• eq: Equal to
• neq: Not equal to
• gte: Greater than or equal to
• lte: Less than or equal to
• like: Pattern matching
• ilike: Case-insensitive pattern matching

Here's an example using some of these filters:

// Filter customers with first name 'John'
async function getCustomersNamedJohn() {
  let { data, error } = await supabase
    .from('customers')
    .select('*')
    .eq('first_name', 'John')

  if (error) console.log('Error:', error)
  else console.log('Data:', data)
}

getCustomersNamedJohn()

// Filter customers whose last name starts with 'Do'
async function getCustomersWithLastNameStartingWithDo() {
  let { data, error } = await supabase
    .from('customers')
    .select('*')
    .like('last_name', 'Do%')

  if (error) console.log('Error:', error)
  else console.log('Data:', data)
}

getCustomersWithLastNameStartingWithDo()

 

Step 6: Combine Multiple Filters

 

You can combine multiple filters to retrieve more specific data:

// Filter customers named 'John' with age greater than or equal to 25
async function getSpecificCustomers() {
  let { data, error } = await supabase
    .from('customers')
    .select('*')
    .eq('first_name', 'John')
    .gte('age', 25)

  if (error) console.log('Error:', error)
  else console.log('Data:', data)
}

getSpecificCustomers()

 

Conclusion

 

By following the steps above, you can effectively query and filter data in your Supabase database using the JavaScript client. The flexibility of the query filters allows you to tailor your data requests precisely to your needs.