这个 MySQL/Java 准备语句语法有什么问题？

Question

我构建了一个小程序，用于循环数据库中的密码列表，对它们进行哈希处理，并使用哈希后的密码更新数据库。我已经更改了列的长度，以确保密码不会太长。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);

问题是每次我运行程序都会出现以下错误：

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)

我已经分解了语法并单独在数据库中进行了尝试，它运行良好，我准备好的语句中是否遗漏了什么？

Answer 1

替换

result = statement.executeUpdate(sqlInsert);

与

result = statement.executeUpdate();

第一个方法在基础 Statement 接口中定义，将在没有绑定参数的情况下执行给定的 SQL 更新字符串。您需要使用 PreparedStatement.

中定义的那个

这个 MySQL/Java 准备语句语法有什么问题？

What is wrong with this MySQL/Java prepared statement syntax?

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mysql

sql

web-applications

jdbc