Question

我有一个小程序，我已经构建了从数据库中循环密码列表，哈希它们，并使用哈希密码更新数据库。我已经改变了列长度，以确保密码不会很长。然后我将其写入我的方法，该方法应该将值写入数据库。

    sqlInsert = "UPDATE dealers SET Password = ?, Password2 = ?, PasswordID = ? WHERE DNo = ?";
    PreparedStatement statement = connect.prepareStatement(sqlInsert);
    statement.setString(1, pw2);
    statement.setString(2, pw1);
    statement.setString(3, pId);
    statement.setString(4,  dId);
    result = statement.executeUpdate(sqlInsert);

问题是每次运行程序时都会出现以下错误：

Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '?, Password2 = ?, PasswordID = ? WHERE DNo = ?' at line 1
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in     your SQL syntax; check the manual that corresponds to your MySQL server version     for the right syntax to use near '?, Password2 = ?, PasswordID = ? WHERE DNo =         ?' at line 1
    at sun.reflect.GeneratedConstructorAccessor7.newInstance(Unknown Source)
    at     sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorA    ccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
    at com.mysql.jdbc.Util.getInstance(Util.java:384)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1052)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4232)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4164)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2615)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2776)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2832)
    at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1755)
    at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1679)
    at     com.secureautodata.business.data.KeyGenerator.encInsert(KeyGenerator.java:99)
at com.secureautodata.business.data.KeyGenerator.main(KeyGenerator.java:392)

我已经打破了语法并在数据库中单独尝试了它并且工作正常，我准备好的语句中是否有一些我缺少的东西？

Answer 1

替换

result = statement.executeUpdate(sqlInsert);

与

result = statement.executeUpdate();

第一个方法在基本Statement接口中定义，并且将执行给定的SQL更新字符串而不使用绑定参数。您需要使用PreparedStatement中定义的那个。

这个MySQL / Java预处理语句语法有什么问题？

1 个答案: