java - SQL 语法错误 : when passing nested query in executeQuery() method

Question

抱歉问了这么愚蠢的问题。

下面是实际的查询:

SELECT  DATE_FORMAT(b.maxtime, "%H:%i") as ts, b.max_value-b.min_value as 
diff FROM (SELECT max(Anzahl) as max_value ,min(Anzahl) as min_value,  
greatest(max(ts),min(ts)) as maxtime  
FROM customer where ts rlike '^2017-06-06' and Typ="B4A"
GROUP BY hour(ts)) b;   

当我使用 java 将其传递到 executeQuery() 方法时，如下所示:

resultset =statement.executeQuery("SELECT DATE_FORMAT(b.maxtime,\"%H:%i\") 
as ts, b.max_value-b.min_value as diff(SELECT max(Anzahl) as max_value 
,min(Anzahl) as min_value, max(ts) as maxtime from customer where Typ = " + 
"\"" + selected_value+"\""+" "+"and ts RLIKE"+"'^"+cal_value+"'"+ "GROUP BY 
hour(ts))b");

我在 SQL 语法中遇到错误。错误是:

MySQL server version for the right syntax to use near '(SELECT max(Anzahl) as max_value ,min(Anzahl) as min_value, max(ts) as maxtime f' at line 1

有人可以帮我解决这个问题吗？

Answer 1

这是一个错字。在实际查询中，...b.min_value 之后有一个 FROM 作为差异。您已将其遗漏在要解析为 executeQuery()

的字符串中

...diff FROM (SELECT max(Anzahl)...

<小时/>

所以完整的声明是

resultset = statement.executeQuery("SELECT DATE_FORMAT(b.maxtime,\"%H:%i\") 
as ts, b.max_value-b.min_value as diff FROM (SELECT max(Anzahl) as max_value 
,min(Anzahl) as min_value, max(ts) as maxtime from customer where Typ = " + 
"\"" + selected_value+"\""+" "+"and ts RLIKE"+"'^"+cal_value+"'"+ "GROUP BY 
hour(ts))b");