
Abstract base class for data providers accessing the data of an IDbConnection. The concrete implementations in this assembly are the OleDbConnectionDataProvider Class, the OracleConnectionDataProvider Class and the SqlConnectionDataProvider Class. You can add your own custom IDbConnection consuming descendants if you can access the database schema information (tables and relations) for your .NET data provider. This class is serializable.
In order to write your own descendant, override the Init() method and pass all tables and relations to the protected Provider member. See the example below for how this is done in the SqlConnectionDataProvider Class. As long as your provider conforms to ISO SQL, you shouldn't need to change anything else, the base class takes care of the entire SQL handling automatically.
Override the OnTranslateFilterSyntax method in order to change the default handling for filter syntax translation. See IAdvancedFiltering Interface for details and see the example below for how this method is overridden in the OracleConnectionDataProvider Class. In this case, just the handling of the SUBSTRING SQL function is changed, as the name of this function is SUBSTR in Oracle.
'Declaration
Public MustInherit Class DbConnectionDataProvider Implements ICanHandleUsedIdentifiers, IDataProvider, combit.Reporting.ISupportsLogger
public abstract class DbConnectionDataProvider : ICanHandleUsedIdentifiers, IDataProvider, combit.Reporting.ISupportsLogger
public ref class DbConnectionDataProvider abstract : public ICanHandleUsedIdentifiers, IDataProvider, combit.Reporting.ISupportsLogger
protected override void Init() { if (Initialized) return; List<String> passedRelationNames = new List<string>(); Connection.Open(); try { DataTable dt = (Connection as SqlConnection).GetSchema("Tables"); foreach (DataRow dr in dt.Rows) { string tableSchema = dr["TABLE_SCHEMA"].ToString(); string tableType = dr["TABLE_TYPE"].ToString(); string parentTableName = dr["TABLE_NAME"].ToString(); switch (tableType) { case "BASE TABLE": if ((SupportedElementTypes & DbConnectionElementTypes.Table) == 0) continue; break; case "VIEW": if ((SupportedElementTypes & DbConnectionElementTypes.View) == 0) continue; break; default: continue; } // pass table SqlConnection newConnection = DbCommandSetDataProviderHelper.CloneConnection(Connection) as SqlConnection; SqlCommand cmd = new SqlCommand("Select * From \"" + (String.IsNullOrEmpty(tableSchema) ? parentTableName+"\"" : tableSchema + "\".\"" + parentTableName) + "\"", newConnection); Provider.AddCommand(cmd as IDbCommand, parentTableName); // pass relations string commandText = "sp_fkeys @pktable_name = '" + parentTableName + "'"; if (!String.IsNullOrEmpty(tableSchema)) { commandText+= ", @pktable_owner = '"+tableSchema+ "'"; } cmd = new SqlCommand(commandText, Connection as SqlConnection); SqlDataReader reader = cmd.ExecuteReader(); while (reader.Read()) { string childColumnName = reader.GetSqlString(7).ToString(); string parentColumnName = reader.GetSqlString(3).ToString(); // combined primary key, add key field to last relation on stack if (reader.GetInt16(8) > 1) { IDataProvider providerInterface = (Provider as IDataProvider); DbCommandTableRelation lastRelation = providerInterface.Relations[providerInterface.Relations.Count - 1] as DbCommandTableRelation; lastRelation.ChildColumnName += '\t' + childColumnName; lastRelation.ParentColumnName += '\t' + parentColumnName; continue; } string childTableName = reader.GetSqlString(6).ToString(); string relName = reader.GetSqlString(2).ToString() + "2" + childTableName; int relationIndex = 1; string formatString = relName+"{0}"; while (passedRelationNames.Contains(relName)) { relName = String.Format(formatString, relationIndex); relationIndex++; } passedRelationNames.Add(relName); Provider.AddRelation(relName, parentTableName, childTableName, parentColumnName, childColumnName); } reader.Close(); } } finally { Connection.Close(); Initialized = true; } }
Protected Overloads Overrides Sub Init() If Initialized Then Return End If Dim passedRelationNames As List(Of [String]) = New List(Of String)() Connection.Open() Try Dim dt As DataTable = (TryCast(Connection, SqlConnection)).GetSchema("Tables") For Each dr As DataRow In dt.Rows Dim tableSchema As String = dr("TABLE_SCHEMA").ToString() Dim tableType As String = dr("TABLE_TYPE").ToString() Dim parentTableName As String = dr("TABLE_NAME").ToString() Select Case tableType Case "BASE TABLE" If (SupportedElementTypes And DbConnectionElementTypes.Table) = 0 Then Continue Select End If Exit Select Case "VIEW" If (SupportedElementTypes And DbConnectionElementTypes.View) = 0 Then Continue Select End If Exit Select Case Else Continue Select End Select ' pass table Dim newConnection As SqlConnection = TryCast(DbCommandSetDataProviderHelper.CloneConnection(Connection), SqlConnection) Dim cmd As New SqlCommand("Select * From """ + (If([String].IsNullOrEmpty(tableSchema), parentTableName + """", tableSchema + """.""" + parentTableName)) + """", newConnection) Provider.AddCommand(TryCast(cmd, IDbCommand), parentTableName) ' pass relations Dim commandText As String = "sp_fkeys @pktable_name = '" + parentTableName + "'" If Not [String].IsNullOrEmpty(tableSchema) Then commandText += ", @pktable_owner = '" + tableSchema + "'" End If cmd = New SqlCommand(commandText, TryCast(Connection, SqlConnection)) Dim reader As SqlDataReader = cmd.ExecuteReader() While reader.Read() Dim childColumnName As String = reader.GetSqlString(7).ToString() Dim parentColumnName As String = reader.GetSqlString(3).ToString() ' combined primary key, add key field to last relation on stack If reader.GetInt16(8) > 1 Then Dim providerInterface As IDataProvider = (TryCast(Provider, IDataProvider)) Dim lastRelation As DbCommandTableRelation = TryCast(providerInterface.Relations(providerInterface.Relations.Count - 1), DbCommandTableRelation) lastRelation.ChildColumnName += ControlChars.Tab + childColumnName lastRelation.ParentColumnName += ControlChars.Tab + parentColumnName Continue While End If Dim childTableName As String = reader.GetSqlString(6).ToString() Dim relName As String = reader.GetSqlString(2).ToString() + "2" + childTableName Dim relationIndex As Integer = 1 Dim formatString As String = relName + "{0}" While passedRelationNames.Contains(relName) relName = [String].Format(formatString, relationIndex) System.Math.Max(System.Threading.Interlocked.Increment(relationIndex),relationIndex - 1) End While passedRelationNames.Add(relName) Provider.AddRelation(relName, parentTableName, childTableName, parentColumnName, childColumnName) End While reader.Close() Next Finally Connection.Close() Initialized = True End Try End Sub
protected override void OnTranslateFilterSyntax(object sender, TranslateFilterSyntaxEventArgs e) { switch (e.ArgumentType) { case LlExpressionArgumentType.Function: switch (e.Name.ToString().ToUpper()) { case "MID$": if (e.ArgumentCount == 2) e.Result = (String.Format("(SUBSTR({0},{1}))", e.Argument1.ToString(), e.Argument2.ToString() + "+1")); else e.Result = (String.Format("(SUBSTR({0},{1},{2}))", e.Argument1.ToString(), e.Argument2.ToString() + "+1", e.Argument3.ToString())); break; case "LEFT$": e.Result = (String.Format("(SUBSTR({0},0,{1}))", e.Argument1.ToString(), e.Argument2.ToString())); break; case "RIGHT$": e.Result = (String.Format("(SUBSTR({0},-{1},{1}))", e.Argument1.ToString(), e.Argument2.ToString())); break; default: e.Result = null; break; } break; default: e.Result = null; break; } }
System.Object
combit.Reporting.DataProviders.DbConnectionDataProvider
combit.Reporting.DataProviders.CDataDataProvider
combit.Reporting.DataProviders.DB2ConnectionDataProvider
combit.Reporting.DataProviders.OdbcConnectionDataProvider
combit.Reporting.DataProviders.OleDbConnectionDataProvider
combit.Reporting.DataProviders.OracleConnectionDataProvider
combit.Reporting.DataProviders.SqlConnectionDataProvider
combit.Reporting.DataProviders.SQLiteConnectionDataProvider