根据MSDN文章 ^ ]，则OLEDB提供程序不支持参数的Sql样式.由于它不支持命名参数，因此它们表示为

According to MSDN article here[^], the OLEDB Provider does not support the Sql Style of Parameters. As it does not support the named parameters, they state as

因此，将OleDbParameter对象添加到OleDbParameterCollection的顺序必须直接对应到命令文本中参数的问号占位符的位置.

Therefore, the order in which OleDbParameter objects are added to the OleDbParameterCollection must directly correspond to the position of the question mark placeholder for the parameter in the command text.

将代码更改为如下所示:

Change your code to look like the following:

string insertCMD = "INSERT INTO Users (Usern,Passw,RegisterEmail) VALUES (?,?,?)";

和

and

insertCMD.Parameters.Add(textEdit1.Text);
insertCMD.Parameters.Add(textEdit2.Text);
insertCMD.Parameters.Add(textEdit3.Text);

这有帮助吗?

Does this help?

如果您的数据库表包含使用Microsoft Jet 4.0保留字的列名，则可能会出现此问题. PASSWORD是此处的关键字 [ MS支持:您可能会收到"INSERT INTO语句中的语法错误"错误消息 [ ^ ]

This problem may occur if your database table contains column names that use Microsoft Jet 4.0 reserved words.
PASSWORD is a KEYWORD here[^] and thus an error.

Change the column name to get away with the error.

Details, refer here: MS Support: You may receive a "Syntax error in INSERT INTO statement" error message [^]