SQL 语法错误：SELECT WXG, CSIG 错误分析及解决方法

The SQL syntax is incorrect. It looks like there are two subqueries but they are not properly enclosed within parentheses. Here is a corrected version of the query:

SELECT WXG, CSIG FROM ( SELECT count(distinct AppIdentifier) AS WXG FROM log_iMonkey_iOS_overview WHERE AppIdentifier IN ('com.tencent.qy.xin','com.tencent.vphoenix.db') GROUP BY AppIdentifier ) AS subquery1 JOIN ( SELECT count(distinct AppIdentifier) AS CSIG FROM log_iMonkey_iOS_overview WHERE AppIdentifier IN ('com.tencent.meeting.dev','com.tencent.fx.rtmpdemo2','com.tencent.tx.image.demo','com.tencent.TTNews.db','com.tencent.sosomap.dailybuild','com.tx.image.demo') GROUP BY AppIdentifier ) AS subquery2 ON 1=1;

This query uses a join to combine the results of the two subqueries. The ON clause with 1=1 is used to return all possible combinations of rows from the two subqueries.