Google bigquery BigQuery UDF为给定函数参数定义常量字典和匹配
定义映射的最佳方式是什么:映射(1->“一”,2->“二”)并定义与上述函数匹配的函数?我正在考虑通过Javascript定义一个字典,并在函数体中进行匹配。举个例子就好了。感谢下面的BigQuery标准SQL示例Google bigquery BigQuery UDF为给定函数参数定义常量字典和匹配,google-bigquery,user-defined-functions,Google Bigquery,User Defined Functions,定义映射的最佳方式是什么:映射(1->“一”,2->“二”)并定义与上述函数匹配的函数?我正在考虑通过Javascript定义一个字典,并在函数体中进行匹配。举个例子就好了。感谢下面的BigQuery标准SQL示例 #standardSQL CREATE TEMP FUNCTION MAP(expr ANY TYPE, map ANY TYPE, `default` ANY TYPE ) AS ( IFNULL(( SELECT result FROM (SELECT NU
#standardSQL
CREATE TEMP FUNCTION MAP(expr ANY TYPE, map ANY TYPE, `default` ANY TYPE ) AS (
IFNULL((
SELECT result
FROM (SELECT NULL AS search, NULL AS result UNION ALL SELECT * FROM UNNEST(map))
WHERE search = expr), `default`)
);
WITH `project.dataset.table` AS (
SELECT 1 id, 4 location_id UNION ALL
SELECT 2, 2 UNION ALL
SELECT 3, 5
)
SELECT id, location_id,
MAP(location_id,
[ (1, 'Los Angeles'),
(2, 'San Francisco'),
(3, 'New York'),
(4, 'Seattle')
], 'Non US') AS `Location`
FROM `project.dataset.table`
结果
Row id location_id Location
1 1 4 Seattle
2 2 2 San Francisco
3 3 5 Non US
不想大肆宣扬,但为什么不创建一个映射表并使用普通的SQL联接呢?