山娃—山沟里的孩子

摘要： This is a common but frustrating error that can create real problems. The cause for this error is one or more of the following: A primary key for the table is not listed in the Update Properties for the DataWindow.The primary key selected allows and has duplicates.The Update Properties for the Dat.. 阅读全文

摘要： 先删除子表信息，然后修改主表的主键信息，最后再添加子表信息。直接修改不行，有主外键约束。所以执行以上操作。 阅读全文