參數索引超出範圍（2>參數數量爲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

刪除問號周圍的引號。

Answer 2

單引號圍繞佔位符字符引起此錯誤。刪除它們：

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