Joining External Database Information

Kyle Brodbeck — Fri, 07 Oct 2005 13:30:00 GMT

I recently received a request to join data from an external ODBC data source to the internal results of a SharePoint search. To be specific, the client wished to outer join SQL data on SharePoint’s search results. Ideally, one would create a custom SQL data source and modify SharePoint’s SQL query to do the join. This solution would scale much better than the one I ended up implementing and describe below. In this example, I’ll use the hypothetical situation of incorporating HR information with the People information stored in SharePoint.

To join across the disparate sources I’ll use the users’ SAMAccountName, which is stored in the database as ‘urn:schemas-microsoft-com:sharepoint:portal:profile:AccountName’. You could have just as easily used an employee ID that has been pushed to AD, but you must remember to include it in the indexing. My approach assumes that for each employee you also have their login stored in the database. I began by overriding the Search Results web part:

public class MySearch : Microsoft.SharePoint.Portal.WebControls.SearchResults

{

protected Xml xmlResults = new Xml();

protected DataSet dsResults;

protected string strOut;

private const string strConn = "data source=XYZ; initial catalog= XYZ; user id= XYZ; password= XYZ; persist security info=True";

Then we must modify the select statement of the query to include our joining property. It should look something like:

protected override string GenerateQueryString(string strKeyword,

System.Collections.ArrayList rgScopeList, string

strWhereAndPart, out string strSavedQuery)

{

string strSelect = base.QueryTemplateSelectPart;

strSelect = "SELECT \"urn:schemas-microsoft-com:sharepoint:portal:profile:AccountName\", " + strSelect.Substring(6);

base.QueryTemplateSelectPart = strSelect;

return base.GenerateQueryString (strKeyword, rgScopeList,

strWhereAndPart, out strSavedQuery);

}

The next step is to intercept the result and return it as a dataset:

protected override object IssueQuery(string strQuery,

int startRowIndex, int endRowIndex)

{

dsResults = (DataSet) base.IssueQuery(strQuery,

startRowIndex, endRowIndex);

return dsResults;

}

Once the base dataset is created we’ll have to add the desired columns for which we will populate with our HR database information. Then we can retrieve our HR database information, which we’ll do by executing a stored procedure and return those results into a separate dataset. All of the code that follows is implemented in the overridden CreateChildControls function.

dsResults.Tables["Table"].Columns.Add("EmpID");

dsResults.Tables["Table"].Columns.Add("BillRate");

dsResults.Tables["Table"].Columns.Add("MoreHRInfo");

dsResults.Tables["Table"].Columns.Add("IconURL");

SPWeb currWeb = SPControl.GetContextWeb(Context);

SqlConnection objConn = new SqlConnection(strConn);

SqlCommand cmdSQL = new SqlCommand("proc_EmployeeData", objConn);

cmdSQL.CommandType = CommandType.StoredProcedure;

cmdSQL.Parameters.Add("@SAMAccountName",

currWeb.CurrentUser.LoginName.Trim());

objConn.Open();

SqlDataAdapter daSQL = new SqlDataAdapter();

daSQL.SelectCommand = cmdSQL;

DataSet dsSQL = new DataSet();

daSQL.Fill(dsSQL, "myTable");

objConn.Close();

Since the two datasets likely won’t have a parent child relationship, we won’t be able to join them using dataset/datatable relations. Instead, you can do a manual join by filtering the SharePoint dataset down to the desired class of objects, such as SPSPeople for people, and then doing a find on the dataset’s PrimaryKey field, which we set to be the Username. This has the effect of joining on their joining field (SAMAccountName to Username). Where they match you can insert the data from the desired SQL field into the created field on the SharePoint dataset.

dsSQL.Tables["myTable"].PrimaryKey = new DataColumn[]

{dsSQL.Tables["myTable"].Columns["Username"] };

string tmpLogin;

string tmpVal;

for(int i=0; i

{

tmpVal = dsResults.Tables["Table"].Rows[i]["DAV:displayname"].ToString().Trim();

if(dsResults.Tables["Table"].Rows[i]["DAV:contentclass"].ToString().Trim() == "urn:content-class:SPSPeople")

{

//ItemArray[1] is the index of the AccountName in the

//select statement we created.

//Substring(x) is used to eliminate the ‘Domain\’

//prefix of the AccountName

tmpLogin = dsResults.Tables["Table"].Rows[i].ItemArray[1].ToString().Substring(7);

DataRow myRow = dsSQL.Tables["myTable"].Rows.Find(tmpLogin.Trim());

if (myRow != null)

{

dsResults.Tables["Table"].Rows[i]["EmpID"] = myRow["HREmpID"].ToString().Trim();

dsResults.Tables["Table"].Rows[i]["BillRate"] = myRow["HRBillRate"].ToString().Trim();

dsResults.Tables["Table"].Rows[i]["MoreHRInfo"] = myRow["MoreData"].ToString().Trim();

}

else

{

if(tmpVal.LastIndexOf(".") != -1)

{

dsResults.Tables["Table"].Rows[i]["IconURL"] = SPUtility.MapToIcon(currWeb, tmpVal, "");

}

Once the datasets are built, we must rebuild the presentation layer. I accomplished this by obtaining the XML data from the dataset and applying an XSL transformation. Note the else condition in the previous code block for when the class is not ‘SPSPeople’. This is necessary to determine the icon to display.

xmlResults.TransformSource = "_layouts/custom/xsl/Transform.xsl";

xmlResults.DocumentContent = dsResults.GetXml();

In my next post, I will focus on the XSL file to build the presentation layer and will also make the CS file available for the above example.