将现有列标记为数据表中的主键 [英] marking existing column as primary key in datatable

问题描述

我希望该datatable具有现有列的主键。

我该怎么做？

解决方案

假设数据中的列名称你想成为主键的表被称为 pk_column ，你可以这样做（假设 dt 是你的 DataTable ）：

  dt.PrimaryKey = new DataColumn [] {dt.Columns [ pk_column]}; 
  

如果您的主键由多列组成，可以将它们添加到数组中，如：

  dt.PrimaryKey = new DataColumn [] {dt.Columns [pk_column1]，dt.Columns [pk_column2 ]}; 
  

所以如果你正在做student_id你的主键，你可以这样做：

  dt.PrimaryKey = new DataColumn [] {dt.Columns [student_id]}; 
  

I have a datatable from database on the basis of some query.

I want that datatable to have a primary key for an existing column.

How can I do this?

解决方案

Assuming the name of the column in your data table you want to be the primary key is called pk_column, you could do this (assume dt is your DataTable):

dt.PrimaryKey = new DataColumn[] { dt.Columns["pk_column"] };

If your primary key is made up of multiple columns, you can add them to the array, like so:

dt.PrimaryKey = new DataColumn[] { dt.Columns["pk_column1"], dt.Columns["pk_column2"] };

So if you were making student_id your primary key, you could do this:

dt.PrimaryKey = new DataColumn[] { dt.Columns["student_id"] };

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