我正在尝试编写一个获取id u(整数)的小函数,并返回距离为我写了这个简单的查询:
String likesDistance =
"SELECT uid2 " + //DISTANCE = 1
"FROM Likes " +
"WHERE uid1 = ? " +
"UNION " +
"SELECT L2.uid2 " + //DISTANCE = 2
"FROM Likes L1, Likes L2 " +
"WHERE L1.uid1 = ? and L1.uid2 = L2.uid1 " +
"UNION "+
"SELECT L3.uid2 " + //DISTANCE = 3
"FROM Likes L1, Likes L2 , Likes L3 " +
"WHERE L1.uid1 = ? and L1.uid2 = L2.uid1 and L2.uid2 = L3.uid1 ";
然后,我执行以下操作:
PreparedStatement pstmt2 = con.prepareStatement(likesDistance);
pstmt1.setInt(1, u);
pstmt1.setInt(2, u);
System.out.println("2");
pstmt1.setInt(3, u);
System.out.println("3");
pstmt1.setInt(4, u);
pstmt1.setInt(5, u);
如前所述,其中u是传递给函数的整数。
所有这些代码都在“ try”块内。当我尝试运行它时,它将打印第一个打印输出(“ 2”),而不打印第二个打印输出(“ 3”),并且得到以下异常消息:
列索引超出范围:3,列数:2。
为什么会这样,如何更改它以使其按需工作?
非常感谢。
最佳答案
复制和粘贴?猜猜您想为语句2设置参数。
关于java - 带PreparedStatement的JDBC错误,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/8474629/