.net 将现有列标记为数据表中的主键
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marking existing column as primary key in datatable
提问by NoviceToDotNet
I have a datatable from database on the basis of some query.
我有一个基于某些查询的数据库数据表。
I want that datatable to have a primary key for an existing column.
我希望该数据表具有现有列的主键。
How can I do this?
我怎样才能做到这一点？
回答by dcp
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 dtis your DataTable):
假设你的数据表中你想要成为主键的列的名称被称为pk_column，你可以这样做（假设dt是你的DataTable）：
dt.PrimaryKey = new DataColumn[] { dt.Columns["pk_column"] };
If your primary key is made up of multiple columns, you can add them to the array, like so:
如果您的主键由多列组成，您可以将它们添加到数组中，如下所示：
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:
因此，如果您将 student_id 设为您的主键，您可以这样做：
dt.PrimaryKey = new DataColumn[] { dt.Columns["student_id"] };
回答by Nishank Jain
DataColumn pkCurrencyCodeId = TblCurrencyCode.Columns.Add("CurrencyCodeId", typeof(Int32));
TblCurrencyCode.PrimaryKey = new DataColumn[] { pkCurrencyCodeId };
