如何使用 BIGQUERY 提取数组中每个项目的最后 8 个元素

Question

I have a column that is an array, like ["551199999999","55129999999999","5532999999999]. Using BigQuery, I used JSON_EXTRACT_STRING_ARRAY(column) and I get the items split on a list. Now, I want to get the last 8 string of each item of the array, I've trid RIGHT(JSON_EXTRACT_STRING_ARRAY(column)) but I got an erro. Anyone know how to do that?

Answer 1

You need to UNNEST an array first and apply RIGHT() function to each item of the array like below.

 WITH sample AS (
   SELECT '["551199999999","55129999999999","5532999999999"]' json
 )
 SELECT RIGHT(item, 8) 
   FROM sample, UNNEST(JSON_VALUE_ARRAY(json)) item;

-- Query results
+-----+----------+
| Row |   f0_    |
+-----+----------+
|   1 | 99999999 |
|   2 | 99999999 |
|   3 | 99999999 |
+-----+----------+

And prefer to use new JSON functions instead of using legacy ones.

• https://cloud.google.com/bigquery/docs/reference/standard-sql/json_functions#standard_json_extraction_functions_recommended