java - 参数索引超出范围（2 > 参数个数，即 1）

Question

String query = "insert into dept values(?,'?','?'))";
PreparedStatement pu=con.prepareStatement(query);
pu.setInt(1, 2);
pu.setString(2, "a");
pu.setString(3, "ss");
pu.execute(query);

Answer 1

删除问号周围的引号。

Answer 2

占位符字符周围的单引号导致此错误。删除它们：

String query = "insert into dept values(?,?,?))";