Google bigquery 如何在联接查询中选择两次相同的列？

当M或F时，我如何计算性别

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由于您没有描述表的结构并使用西班牙语标识符，因此我将使用一个更清晰的示例来说明我自己的模式：

SELECT
   SUM( CASE WHEN Sex = 'M' THEN 1 ELSE 0 END ) AS M,
   SUM( CASE WHEN Sex = 'F' THEN 1 ELSE 0 END ) AS F
FROM  People
WHERE People.Dept = 5

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由于您没有描述表的结构并使用西班牙语标识符，因此我将使用一个更清晰的示例来说明我自己的模式：

SELECT
   SUM( CASE WHEN Sex = 'M' THEN 1 ELSE 0 END ) AS M,
   SUM( CASE WHEN Sex = 'F' THEN 1 ELSE 0 END ) AS F
FROM  People
WHERE People.Dept = 5

SELECT
   SUM( CASE WHEN Sex = 'M' THEN 1 ELSE 0 END ) AS M,
   SUM( CASE WHEN Sex = 'F' THEN 1 ELSE 0 END ) AS F
FROM  People
WHERE People.Dept = 5