Google BigQuery相当于MySQL多表内部联接

Question

我想知道如何在Google BigQuery中编写类似于以下针对MySQL的多表联接：

SELECT t2.*, t1.*, t3.* FROM table1 t1, table2 t2, table t3 WHERE t1.field_a=t2.field_a AND t2.field_b=t3.field_b AND t1.field_condition=10

请注意，我请求表的顺序为特定顺序，但使用星号功能。

有什么想法吗？

Answer 1

当列与名称匹配时（如在问题中），较短的一个：

#standardSQL
WITH t_a AS (SELECT 1 id_a, 2 v)
, t_b AS (SELECT 1 id_a, 2 id_c, 3 w)
, t_c AS (SELECT 2 id_c, 5 z)

SELECT *
FROM t_a
JOIN t_b USING(id_a)
JOIN t_c USING(id_c)

Answer 2

以下是用于BigQuery标准SQL

#standardSQL
SELECT t2.*, t1.*, t3.* 
FROM table1 t1
JOIN table2 t2 ON t1.field_a=t2.field_a 
JOIN table t3 ON t2.field_b=t3.field_b 
WHERE t1.field_condition=10

以上假设字段名称中没有歧义

同时，以下内容仍适用于BigQuery Standard SQL

SELECT t2.*, t1.*, t3.* FROM table1 t1, table2 t2, table t3 WHERE t1.field_a=t2.field_a AND t2.field_b=t3.field_b AND t1.field_condition=10   

并等于

#standardSQL
SELECT t2.*, t1.*, t3.* FROM table1 t1
CROSS JOIN table2 t2
CROSS JOIN table t3 
WHERE t1.field_a=t2.field_a AND t2.field_b=t3.field_b AND t1.field_condition=10