在GoogleSql Bigquery中使用where子句和Union子句。

Question

我试图将两个表联合起来，比较一个匹配的字段，但我收到以下错误:-"SQL_ANALYSIS_ERROR: Unrecognized name: t2 (Line: 87, Column: 121) "其中t2被重命名为我的第二个表。

这是我的代码：-

CREATE OR REPLACE TABLE table_1 OPTIONS (
  quota_accounting_owner='[email protected]')
AS 
  SELECT * FROM
  (
  SELECT * EXCEPT(fate_result), CAST(fate_result AS STRING) AS fate_result FROM table_1 AS t1 WHERE t2.e_id <> t1.e_id
  UNION DISTINCT
  SELECT * EXCEPT(fate_result), CAST(fate_result AS STRING) AS fate_result FROM table_2 AS t2
    );

Answer 1

你可以使用 NOT EXISTS 的行，只选择 table_1 不匹配的 e_id 在 table_2

CREATE OR REPLACE TABLE table_1 OPTIONS (
  quota_accounting_owner='[email protected]')
AS 
  SELECT * FROM
  (
    SELECT * EXCEPT(fate_result), CAST(fate_result AS STRING) AS fate_result
    FROM table_1 AS t1
    WHERE NOT EXISTS (
       SELECT 1
       FROM table_2 AS t2
       WHERE t2.e_id = t1.e_id
    )
    UNION DISTINCT
    SELECT * EXCEPT(fate_result), CAST(fate_result AS STRING) AS fate_result
    FROM table_2 AS t2
  );

编辑 NOT EXISTS对于标准SQL来说是正确的选择，但是看到下面的评论，这里会抛出一个错误，所以NOT IN可能更好。

CREATE OR REPLACE TABLE table_1 OPTIONS (
  quota_accounting_owner='[email protected]')
AS 
  SELECT * FROM
  (
    SELECT * EXCEPT(fate_result), CAST(fate_result AS STRING) AS fate_result
    FROM table_1 AS t1
    WHERE t1.e_id NOT IN (
       SELECT t2.ed_id
       FROM table_2 AS t2
    )
    UNION DISTINCT
    SELECT * EXCEPT(fate_result), CAST(fate_result AS STRING) AS fate_result
    FROM table_2 AS t2
  );