DatabaseProvider.ExecuteQuery Method
Returns an array of query results after executing a database query.
Namespace: Microsoft.Web.Management.DatabaseManager
Assembly: Microsoft.Web.Management.DatabaseManager (in Microsoft.Web.Management.DatabaseManager.dll)
Syntax
'Declaration
Public MustOverride Function ExecuteQuery ( _
connectionString As String, _
query As Query _
) As QueryResult()
'Usage
Dim instance As DatabaseProvider
Dim connectionString As String
Dim query As Query
Dim returnValue As QueryResult()
returnValue = instance.ExecuteQuery(connectionString, _
query)
public abstract QueryResult[] ExecuteQuery(
string connectionString,
Query query
)
public:
virtual array<QueryResult^>^ ExecuteQuery(
String^ connectionString,
Query^ query
) abstract
public abstract function ExecuteQuery(
connectionString : String,
query : Query
) : QueryResult[]
Parameters
- connectionString
Type: System.String
The connection string for the database connection.
- query
Type: Microsoft.Web.Management.DatabaseManager.Query
The Query object that contains the query statement to execute.
Return Value
Type: array<Microsoft.Web.Management.DatabaseManager.QueryResult[]
An array of QueryResult objects.
Remarks
Your provider must implement the ExecuteQuery method in order to submit database queries for your provider.
Examples
The following code sample illustrates an example ExecuteQuery method that returns an array of query results from a database query.
Public Overrides Function ExecuteQuery( _
ByVal connectionString As String, _
ByVal query As Microsoft.Web.Management.DatabaseManager.Query) _
As Microsoft.Web.Management.DatabaseManager.QueryResult()
Dim results As List(Of QueryResult) = New List(Of QueryResult)
Dim result As QueryResult = New QueryResult
Try
' Create a new OLEDB connection using the connection string.
Dim connection As OleDbConnection = New OleDbConnection(connectionString)
Dim command As OleDbCommand = New OleDbCommand(query.Statement, connection)
' Open the database connection.
connection.Open()
' Execute the query and access the data.
Dim reader As OleDbDataReader = command.ExecuteReader
' Add the results to the query list.
results.Add(GetQueryResult(reader))
' Close the database connection.
reader.Close()
' Return the query results.
Return results.ToArray
Catch ex As Exception
Throw New ProviderException(ex.Message)
End Try
End Function
...
Private Function GetQueryResult(ByVal reader As OleDbDataReader) As QueryResult
Dim result As QueryResult = New QueryResult
Dim fieldCount As Integer = reader.FieldCount
Dim i As Integer = 0
Do While (i < fieldCount)
Dim metadata As QueryColumnMetadata = New QueryColumnMetadata
metadata.Name = reader.GetName(i)
result.ColumnMetadata.Add(metadata)
i = (i + 1)
Loop
While reader.Read
Dim itemData() As Object = New Object((fieldCount) - 1) {}
i = 0
Do While (i < fieldCount)
itemData(i) = ConvertToSerializable(reader(i))
i = (i + 1)
Loop
result.QueryResults.Add(itemData)
End While
Return result
End Function
public override QueryResult[] ExecuteQuery(
string connectionString,
Query query )
{
List<QueryResult> results = new List<QueryResult>();
QueryResult result = new QueryResult();
try
{
// Create a new OLEDB connection using the connection string.
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
OleDbCommand command = new OleDbCommand(query.Statement, connection);
// Open the database connection.
connection.Open();
// Execute the query and access the data.
OleDbDataReader reader = command.ExecuteReader();
// Add the results to the query list.
results.Add(GetQueryResult(reader));
// Close the database connection.
reader.Close();
}
// Return the query results.
return results.ToArray();
}
catch(Exception ex)
{
throw new ProviderException(ex.Message);
}
}
...
private QueryResult GetQueryResult(OleDbDataReader reader)
{
QueryResult result = new QueryResult();
int fieldCount = reader.FieldCount;
for (int i = 0; i < fieldCount; i++)
{
QueryColumnMetadata metadata = new QueryColumnMetadata();
metadata.Name = reader.GetName(i);
result.ColumnMetadata.Add(metadata);
}
while (reader.Read())
{
object[] itemData = new object[fieldCount];
for (int i = 0; i < fieldCount; i++)
{
itemData[i] = ConvertToSerializable(reader[i]);
}
result.QueryResults.Add(itemData);
}
return result;
}
Permissions
- Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.