java - 如何从 Java 将参数化的 DELETE 发送到 MySql

Question

我想通过以下方式从名为 PersonnelTable 的表中删除:

public void verifyDetailsBeforeClosingAccount(String _idNumber,String _username,String _password ,String _account)
{

    String retrievedNumberAccount = null;
    String retrievedOwnerIdnumber = null;

    try
    {

        // take all the rows with "account-number" and "id-numbder" in the "Checking-account-table" 

        ResultSet results = this.m_statement.executeQuery("SELECT `AccountNumber`, `IdNumber`  FROM `CheckingAccountsTable`");  
        while (results.next() == true)
        {
            retrievedNumberAccount = results.getString("AccountNumber");  // take the account number 
            retrievedOwnerIdnumber = results.getString("IdNumber");       // take the ID number 

            if (retrievedNumberAccount.equals(_account) == true && retrievedOwnerIdnumber.equals(_idNumber) == true )  // found a partial match 
            {
                // put something here
            }
        }
    }
}

我想删除 PersonnelTable 中的一行，其中:

表中的
1. Password 列等于提供给函数的 _password ，
表中的
2. UserName 列等于提供给函数的 _username。

那行不通:

this.m_statement.executeQuery("DELETE FROM `PersonnelTable` WHERE `Password` = _password AND `UserName` =_username ");

我看过 DELETE 的教程，但没有任何内容说明如何将给定值处理为函数。我怎样才能解决这个问题 ？

问候

Answer 1

用单引号将值括起来，因为它是一个字符串。对吧？

this.m_statement.executeQuery("DELETE FROM `PersonnelTable` 
                               WHERE `Password` = '" + _password + "' AND 
                                     `UserName` = '" + _username + "' ");

好多了 Java Prepared Statement 为此。

前

string sqlStatement = "DELETE FROM `PersonnelTable` 
                                   WHERE `Password` = ? AND 
                                         `UserName` = ? ";
PreparedStatement pstmt = con.prepareStatement(sqlStatement);
pstmt.setString(1, _password)
pstmt.setString(2, _username)
pstmt.executeUpdate();