string_to_array函數

Question

我正在使用sting_to_array函數在redshift case聲明中。但是，我得到這樣一個錯誤 -

[0A000] ERROR: Specified types or functions (one per INFO message) not supported on Redshift tables.

可能是什麼問題？

下面是示例代碼 -

SELECT 
    CASE 
    WHEN upper(url) LIKE upper('%utm_source%') 
      THEN (string_to_array(url, '&'))[1] 
END as utm_source, 
FROM 
TEMP.table_data a2; 

Bascially我的網址是這種格式的 -

utm_source=257509081c6f53&utm_medium=internet&utm_campaign=messenger-android&utm_term=search_keyword&utm_content=new_products

我在這裏的目的是爲了只提取utm_ *值

Answer 1

陣列功能並且運營商在Redshift中不支持：http://docs.aws.amazon.com/redshift/latest/dg/c_unsupported-postgresql-functions.html

相反，嘗試使用SPLIT_PART功能：

SELECT 
    CASE 
    WHEN upper(url) LIKE upper('%utm_source%') 
     THEN SPLIT_PART(url, '&', 1) 
    END as utm_source 
FROM 
TEMP.table_data a2; 

注：的SPLIT_PART功能開始從1