Java 查询在MySQL提示符下执行，但不在应用程序中执行

以下查询在MySQL提示符中正确执行，但在Java中出错 您的SQL语法有错误；检查与您的MySQL服务器版本相对应的手册，通过在第1行选择“A+”时选择平均案例等级，然后选择“A”时选择4，然后选择“A-”时选择4，然后选择3.7 w”，以获得正确的语法

java.sql.ResultSet rslt= stmt.executeQuery("select name from student natural join takes t1 where (dept_name='Comp. Sci.')" +
        "group by ID" +
        "order by (select avg( case grade " +
                        "when 'A+' then 4 " +
                        "when 'A' then 4 " +
                        "when 'A-' then 3.7 " +
                        "when 'B+' then 3.5 " +
                        "when 'B' then 3 " +
                        "when 'B-' then 2.7 " +
                        "when 'C+' then 2.5 " +
                        "when 'C' then 2 " +
                        "when 'C-' then 1 " +
                        "end) as avg_gpa " +
                   "from takes t2 " +
               "where t1.ID=t2.ID) " +
        "limit 10");

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有人能帮忙吗？

不要忘记每行后面的空格：

java.sql.ResultSet rslt= stmt.executeQuery(
"select name from student natural join takes t1 where (dept_name='Comp. Sci.') "+
"group by ID "+
"order by (select avg( case grade "+
        "when 'A+' then 4  "+
    "when 'A' then 4 "+
    "when 'A-' then 3.7 "+
    "when 'B+' then 3.5 "+
    "when 'B' then 3 "+
    "when 'B-' then 2.7 "+
    "when 'C+' then 2.5 "+
    "when 'C' then 2 "+
    "when 'C-' then 1 "+
    "end) as avg_gpa "+
    "from takes t2 "+
"where t1.ID=t2.ID) "+
"limit 10");

在sql中，这是错误的：

"group by ID" +
        "order by (select avg( case grade " +

这里有这样一个字符串：group by IDorder by select avg case grade

你看到问题了吗

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在ID之后添加一个空格

我认为这不是您的java代码。如何连接每行中的字符串？我省略了每行中的字符串，只是为了简化这里的代码，而不是java中的代码。。我不明白你说的不是我的java代码是什么意思？请也展示这一部分，我将向你展示问题……只是复制并粘贴了来自javano prob的语句：请随意点击我答案左上方的白色钩子接受。