对表构造适当的索引，使用Join来替代子查询，然后使用exists语法来简化查询语句，可以适当对空结果集进行判断。

是不是没有找IDaaS技术人员开通配置

报错是由于超出单个用户可加入群组数，如果需要拓展可以升级套餐包或者购买增值功能 https://cloud.tencent.com/document/product/269/11673#jcfw 图片 图片

下面的是Spark官方标记支持的： Spark SQL and DataFrames内容非常清楚了

这个图片可能会帮上你的忙 [图片]

以下是包含JOIN＆WHERE两者的更新查询。同样的方法，我们可以使用多个加入/ where子句，希望它会帮助你： - UPDATE opportunities_cstm oc JOIN opportunities o ON oc.id_c = o.id SET oc.forecast_stage_c = 'APX' WHERE o.deleted = 0 AND o.sales_stage IN('ABC','PQR','XYZ')

这里是T-SQL版本： -- Test data DECLARE @TestTable TABLE (id INT, home INT, date DATETIME, player VARCHAR(20), resource INT) INSERT INTO @TestTable SELECT 1, 10, '2009-03-04', 'john', 399 UNION SELECT 2, 11, '2009-03-04', 'juliet', 244 UNION SELECT 5, 12, '2009-03-04', 'borat', 555 UNION SELECT 3, 10, '2009-03-03', 'john', 300 UNION SELECT 4, 11, '2009-03-03', 'juliet', 200 UNION SELECT 6, 12, '2009-03-03', 'borat', 500 UNION SELECT 7, 13, '2008-12-24', 'borat', 600 UNION SELECT 8, 13, '2009-01-01', 'borat', 700 -- Answe SELECT id, home, date, player, resource FROM (SELECT id, home, date, player, resource, RANK() OVER (PARTITION BY home ORDER BY date DESC) N FROM @TestTable )M WHERE N = 1 -- and if you really want only home with max date SELECT T.id, T.home, T.date, T.player, T.resource FROM @TestTable T INNER JOIN ( SELECT TI.id, TI.home, TI.date, RANK() OVER (PARTITION BY TI.home ORDER BY TI.date) N FROM @TestTable TI WHERE TI.date IN (SELECT MAX(TM.date) FROM @TestTable TM) )TJ ON TJ.N = 1 AND T.id = TJ.id

关系代数允许WHERE子句和子句中谓词的可交换性INNER JOIN，所以即使INNER JOIN带有WHERE子句的查询也可以使谓词由优化器重新排列，以便在此过程中它们可能已被排除JOIN。 我建议你尽可能以最可读的方式编写查询。 有时候，这包括使INNER JOIN相对“不完整”，并将一些标准放在WHERE简单的过滤条件列表中，以便更容易维护。 例如，而不是： SELECT * FROM Customers c INNER JOIN CustomerAccounts ca ON ca.CustomerID = c.CustomerID AND c.State = 'NY' INNER JOIN Accounts a ON ca.AccountID = a.AccountID AND a.Status = 1 写： SELECT * FROM Customers c INNER JOIN CustomerAccounts ca ON ca.CustomerID = c.CustomerID INNER JOIN Accounts a ON ca.AccountID = a.AccountID WHERE c.State = 'NY' AND a.Status = 1