使用IDatareader和SqlBulkCopy将Dictionary元素作为行插入SQL表中

Question

I need to improve dramatically the execution time of a process wich currently is just like this:

private Dictionary<int, SingleElement> elements_buffer;

// ... Create and load values into "elements_buffer"
// (string, Datetime, double)

string query = "INSERT INTO Tests.dbo.test_table "
    + "(element_name,element_init,element_width) VALUES";

SingleElement element_aux;

for (int i = 0; i < MAX_ELEMS_IN_DICT; i++)
{
    element_aux = elements_buffer[i];

    query = query
        + "('"
        + element_aux.name
        + "','"
        + element_aux.init
        + "',"
        + element_aux.width
        + ")";

    if (i < MAX_ELEMS_IN_DICT+1) {
        query = query + ",";
    }
}

// ... Execute the query

I was going to use Datatable for the new version, but I've been reading about using SqlBulkCopy together with IDatareader , as mentioned in:

SqlBulkCopy performance

C# loops and mass insert

It looks like to me a better choice for my code, but can't get to figure it out how to code it, though I would like to use it.

Can I have some help with the translated code, please?

Thanks in advance

Answer 1

As you already have figured out, you need to implement custom IDataReader . As your source is Dictionary - only few relatively simple method/properties such as int FieldCount, bool Read(), object Get(int i) should be implemented.

You may find useful examples ( a simple one ) of custom IDataReader implementations by googling sqlbulkcopy custom idatareader .

Also keep in mind that SqlBulkCopy ignores triggers, foreign keys and other constraints and is not able to handle exceptions.