How to unnest and pivot two columns in BigQuery

Question

Say I have a BQ table containing the following information

| id    | test.name     | test.score    |
|----   |-----------    |------------   |
| 1     | a                 


        

Answer 1

Below is generic/dynamic way to handle your case

EXECUTE IMMEDIATE (
  SELECT """
  SELECT id, """ || 
    STRING_AGG("""MAX(IF(name = '""" || name || """', score, NULL)) AS """ || name, ', ') 
  || """
  FROM `project.dataset.table` t, t.test
  GROUP BY id
  """
  FROM (
    SELECT DISTINCT name
    FROM `project.dataset.table` t, t.test
    ORDER BY name
  )
);  

If to apply to sample data from your question - output is

Row     id      a       b       c    
1       1       5       7       null     
2       2       8       null    3