Why does a typed dataset cause an insert rather than an update (causing primary key violation)?

Question

I'm trying to use a dataset to update some rows in a database, simple.

I'm creating a typed dataset instance, disabling constraints, adding a few rows to one table and populating a few of the columns in the rows, including the primary key, with existing and correct primary key values. Yet, when I call update on the data adapter it's throwing a primary key violation .

I'm not providing values for every column, only those I want to update. Why does the adapter not recognise an update is required?

MyDataset dataSet = new MyDataset();
dataSet.EnforceConstraints = false;

Answer 1

只是因为您添加了（）记录...这将它们标记为新的 ，它们将在更新时触发Insert语句。