1. Head over to the Supabase website and log in.
2. Create a new project by filling in the details like project name, database name, and region.
3. Once your project is up, go to the Dashboard.

1. In the Supabase Dashboard, find the "Table Editor" section.
2. Click on "New Table" and set the table name and schema.
3. Add columns to your table, specifying data types and whether they are nullable or have any default values.

1. While creating columns, you can add constraints like NOT NULL, UNIQUE, and PRIMARY KEY.
2. For example, to set a NOT NULL constraint:
   • Click on the column.
   • Enable the NOT NULL checkbox to ensure the column does not accept NULL values.
3. To make a column UNIQUE:
   • Enable the UNIQUE checkbox to ensure all values in the column are distinct.
4. To set a column as a primary key:
   • Click on the PRIMARY KEY checkbox for the column.

1. Navigate to the SQL Editor in the Supabase Dashboard.
2. Write a SQL query to add a check constraint to your table. Here is an example:
   ```sql
   ALTER TABLE your_table_name
   ADD CONSTRAINT valid_age CHECK (age >= 18);
   ```
3. Execute the SQL query, and this will enforce that all entries in the age column must be 18 or older.

1. Navigate to the SQL Editor and create a function that encapsulates your validation logic.
2. Example function to check email format:
   ```sql
   CREATE OR REPLACE FUNCTION validate_email_format()
   RETURNS TRIGGER AS $$
   BEGIN
   IF NEW.email !~ '^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+.[A-Z]{2,}$' THEN
   RAISE EXCEPTION 'Invalid email format';
   END IF;
   RETURN NEW;
   END;
   $$ LANGUAGE plpgsql;
   ```

1. Create a trigger to call the function before insert or update operations.
2. Example trigger:
   ```sql
   CREATE TRIGGER check_email_format
   BEFORE INSERT OR UPDATE ON your_table_name
   FOR EACH ROW
   EXECUTE FUNCTION validate_email_format();
   ```

1. Use client-side libraries (e.g., JavaScript) to validate data before sending it to your Supabase API.

2. For example, using JavaScript to validate email format:
   ```javascript
   function validateEmail(email) {
   const re = /^[a-zA-Z0-9+_.-]+@[a-zA-Z0-9.-]+$/;
   return re.test(String(email).toLowerCase());
   }

   const email = "test@example.com";
   if (!validateEmail(email)) {
   alert('Invalid email format');
   }
   ```

1. Implement error handling in your application to manage validation errors returned by Supabase.

2. Example using JavaScript:
   ```javascript
   const { data, error } = await supabase
   .from('your_table_name')
   .insert({ email: 'test@example.com' });

   if (error) {
   console.error("Validation Error: ", error.message);
   } else {
   console.log('Data inserted successfully:', data);
   }
   ```

Following these steps will help in performing robust data validation within Supabase, ensuring data integrity and consistency.