参数索引超出范围（1 > 参数数量，即 0）。尝试将信息保存到数据库时的输出

Question

我创建了一个小程序，用户必须在其中将数据输入文本字段并从组合框中输入 select 选项。我使用XAMPP创建了一个数据库，并通过网络浏览器为程序创建了相应的table。

数据库名为 activitydb，负责存储程序数据的 table 名为 userdata。

table 中的第一列称为 UserID，它是一个整数，每次添加新条目时都会自动递增。其余的都是具有不同最大长度的varchar。

这是目前程序的源代码：

Connection con = null;
Statement st = null;
try {
    // activitydb = database name
    con = DriverManager.getConnection("jdbc:mysql://localhost:3306/activitydb?zeroDateTimeBehavior=convertToNull", "root", "");
    st = con.createStatement();
    // userdata = table name
    String sqlconn = "INSERT INTO userdata (UserID, LastName, FirstName, MiddleName, Email, Sex, HomeAddress, City, CPUBrand, ComputerType, HardwareSpecs, GPUBrand, GPUType, GPUVRAM)";
    PreparedStatement prdStmt = con.prepareStatement(sqlconn);
    // Input of variable data into corresponding database table
    // First table will be declared as null as it is an Integer designed with an Auto Increment
    prdStmt.setString(1, null);
    prdStmt.setString(2, jTextLastName.getText());
    prdStmt.setString(3, jTextFirstName.getText());
    prdStmt.setString(4, jTextMiddleName.getText());
    prdStmt.setString(5, jTextEmail.getText());
    prdStmt.setString(6, jComboBoxSex.getSelectedItem().toString());
    prdStmt.setString(7, jTextHomeAddress.getText());
    prdStmt.setString(8, jTextCity.getText());
    prdStmt.setString(9, jComboBoxCPUBrand.getSelectedItem().toString());
    prdStmt.setString(10, jComboBoxComputerType.getSelectedItem().toString());
    prdStmt.setString(11, jComboBoxHardwareSpecs.getSelectedItem().toString());
    prdStmt.setString(12, jComboBoxGPUBrand.getSelectedItem().toString());
    prdStmt.setString(13, jComboBoxGPUType.getSelectedItem().toString());
    prdStmt.setString(14, jComboBoxGPUVRAM.getSelectedItem().toString());
    // Do this if something goes wrong
} catch (SQLException err) {
    // Print error message to console for diagnosis
    System.out.println(err.getMessage());
}

对于组合框，我使用 getSelectedItem().toString() 将在其中找到的数据存储为字符串。

单击该按钮将使程序除了在控制台中打印之外什么都不做： Parameter index out of range (1 > number of parameters, which is 0).

Answer 1

您缺少放置值的占位符 ?，您的查询应该是：

String sqlconn = "INSERT INTO userdata (UserID, LastName, FirstName, MiddleName," +
        " Email, Sex, HomeAddress, City, CPUBrand, ComputerType, HardwareSpecs," +
        " GPUBrand, GPUType, GPUVRAM) " +
        "VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";

参数索引超出范围（1 > 参数数量，即 0）。尝试将信息保存到数据库时的输出

Parameter index out of range (1 > number of parameters, which is 0). output when attempting to save information to database

java

xampp

netbeans

jdbc