LINQ to SQL Extension: Batch Deletion with Lambda Expression

re: LINQ to SQL Extension: Batch Deletion with Lambda Expression

Mitchell — Mon, 30 Nov 2009 20:00:48 GMT

Awesome job - the code is great.

I tried implementing it for v4.0 and got everything working great except for table mapping - evidently EF 4.0 does not have any properties for accessing for table mappings (due to the fact that multiple database tables can be mapped to a single entity). Any ideas?

re: LINQ to SQL Extension: Batch Deletion with Lambda Expression

Terry Aney — Tue, 17 Nov 2009 23:02:23 GMT

Using the extension from my url above, you could do something like...

tblMyTables.DeleteBatch( t => ( new [] { val1, val2, val3, val4 } ).Contains( t.col1 ) );

re: LINQ to SQL Extension: Batch Deletion with Lambda Expression

Thrishna — Thu, 23 Jul 2009 19:09:33 GMT

How does this support using a Delete statement with an "IN" clause.

Like: "DELETE FROM tblMyTable WHERE col1 IN (val1,val2, val3, val4)"

re: LINQ to SQL Extension: Batch Deletion with Lambda Expression

Salion — Mon, 07 Jul 2008 08:06:25 GMT

very good.

thanks jeffery zhao.

re: LINQ to SQL Extension: Batch Deletion with Lambda Expression

Terry Aney — Mon, 14 Apr 2008 08:24:40 GMT

Jeffrey, this article inspired me to create an implementation for both the DELETE and UPDATE. Have a read over at www.aneyfamily.com/.../Batch-Updates-and-Deletes-with-LINQ-to-SQL.aspx

I also made some references to this article and how I understood it. If I misrepresented anything, please let me know.

re: LINQ to SQL Extension: Batch Deletion with Lambda Expression

Colin B. — Sun, 06 Apr 2008 07:32:21 GMT

Looking at the view from 30,000 feet - Is it only me who thinks that much of Linq is a giant step backward? I mean, comeon, deleting/inserting multiple records is an extremely common task (in my code anyway) and is accomplished using a trivial SQL statement in ADO.NET. This shouldn't be an exercise in academia!

re: LINQ to SQL Extension: Batch Deletion with Lambda Expression

Terry Aney — Tue, 01 Apr 2008 17:51:23 GMT

If there code available for download at all?

扩展LINQ to SQL：使用Lambda Expression批量删除数据。

Zqin — Thu, 06 Mar 2008 03:19:32 GMT

扩展LINQ to SQL：使用Lambda Expression批量删除数据。

re: LINQ to SQL Extension: Batch Deletion with Lambda Expression

JeffreyZhao — Thu, 06 Mar 2008 02:44:08 GMT

@Richard

That's an interesting idea.

re: LINQ to SQL Extension: Batch Deletion with Lambda Expression

Richard — Wed, 05 Mar 2008 19:18:41 GMT

An alternative approach would be to use the GetCommand method of the DataContext, and alter the command text to delete the matching records. That way, any condition supported by LINQ to SQL is supported.

The delete command will need to look something like:

DELETE

FROM TableName

FROM TableName As D0 INNER JOIN (SELECT ....) As D1

ON (D0.Key1 = D1.Key1 And D0.Key2 = D1.Key2 ...)

where "SELECT ..." is the original command text, and the "ON" clause contains all primary key columns for the table. You can find the primary key columns by using reflection on the entity type:

from p in entityType.GetProperties()

from ColumnAttribute a in p.GetCustomAttributes(typeof(ColumnAttribute), false)

where a.IsPrimaryKey

select new

{

Property = p,

Column = a

};