删除数据表中的主键

发布于 2024-11-28 09:11:10 字数 333 浏览 2 评论 0原文

有没有办法从数据表中删除主键或者有没有办法先删除“PK”的约束，然后删除列本身？

谢谢！

更新：

 dtTable.Columns.Add(new System.Data.DataColumn("PRIMARY_KEY", typeof(System.Int32)));
 dtTable.PrimaryKey = new DataColumn[1] { dtTable.Columns["PRIMARY_KEY"] }; // throws an error
 dtTable.Columns["PRIMARY_KEY"].AutoIncrement = true;

原文

is there a way to remove primary key from the datatable Or is there any way to remove the constraints of "PK" first and then remove the column itself?

Thanks!

UPDATED:

 dtTable.Columns.Add(new System.Data.DataColumn("PRIMARY_KEY", typeof(System.Int32)));
 dtTable.PrimaryKey = new DataColumn[1] { dtTable.Columns["PRIMARY_KEY"] }; // throws an error
 dtTable.Columns["PRIMARY_KEY"].AutoIncrement = true;

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指尖上得阳光 2024-12-05 09:11:10

您可以使用删除主键，

DataTable.PrimaryKey = null;

也可以使用删除数据表列

DataTable.Columns.Remove("column name here");

You can remove primay key using

DataTable.PrimaryKey = null;

you can delete data table column using

DataTable.Columns.Remove("column name here");

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眼眸里的那抹悲凉 2024-12-05 09:11:10

我发现有时从 DataTable 中删除 PrimaryKey 后：

MyDataTable.PrimaryKey = null;

已删除 PrimaryKey 的成员列上的 Unique 设置仍然为 true。

我的解决方案：

 public static void KillPrimaryKey(DataTable LocDataTable)
{
  int LocPriKeyCount = LocDataTable.PrimaryKey.Length;
  string[] PrevPriColumns = new string[LocPriKeyCount];

  // 1. Store ColumnNames in a string Array
  for (int ii = 0; ii < LocPriKeyCount; ii++) PrevPriColumns[ii] = LocDataTable.PrimaryKey[ii].ColumnName;
  // 2. Clear PrimaryKey
  LocDataTable.PrimaryKey = null;
  // 3. Clear Unique settings
  for (int ii = 0; ii < LocPriKeyCount; ii++) LocDataTable.Columns[PrevPriColumns[ii]].Unique = false;
}

I found that sometimes after removing PrimaryKey from a DataTable:

MyDataTable.PrimaryKey = null;

the Unique setting remains true on the member columns of the deleted PrimaryKey.

My solution:

 public static void KillPrimaryKey(DataTable LocDataTable)
{
  int LocPriKeyCount = LocDataTable.PrimaryKey.Length;
  string[] PrevPriColumns = new string[LocPriKeyCount];

  // 1. Store ColumnNames in a string Array
  for (int ii = 0; ii < LocPriKeyCount; ii++) PrevPriColumns[ii] = LocDataTable.PrimaryKey[ii].ColumnName;
  // 2. Clear PrimaryKey
  LocDataTable.PrimaryKey = null;
  // 3. Clear Unique settings
  for (int ii = 0; ii < LocPriKeyCount; ii++) LocDataTable.Columns[PrevPriColumns[ii]].Unique = false;
}

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