Class wwData - West Wind Web Store .NET

Class wwData

This is the base Data interface that is used by wwBusiness to access the
backend database.

This class is an abstract interface that implements only a couple of the
worker methods. Most features are implemented in the concrete classes like
wwDataSql, wwDataOleDb etc.

The concrete classes implemented are:

Classname	Database
wwDataSql	Sql Server
wwDataOleDbVfp	Visual FoxPro via OleDb
wwDataOracle	Oracle
wwDataMySql	My Sql
wwDataVistaDb	VistaDb Engine
wwDataOdbc	Generic Odbc databases
wwDataOleDb	Generic Ole Db databases

This class presents the functional interface of all data classes.

System.Object
Westwind.BusinessObjects.wwData

public abstract class wwData : object, IDisposable

Class Members

Member		Description
	BeginTransaction	Starts a new Transaction on this data object. public virtual IDbTransaction BeginTransaction( IsolationLevel Isolation );
	Close	Closes the database connection public virtual bool Close();
	CopyDataRow	Copies fields from one datarow to another by looking at the target's field list and trying to retrieve the fields with the same name from the source datarow public static void CopyDataRow( DataRow Source, DataRow Target );
	CreateCommand	Creates a command object based on the specified command text and connection public abstract IDbCommand CreateCommand( string cmdText );
	CreateConnection	Creates a new connection based on the ConnectionString property. public abstract IDbConnection CreateConnection();
	CreateDataAdapter	Creates a data adapter object, passing the specified command object in the constructor. public System.Data.IDbDataAdapter CreateDataAdapter(System.Data.IDbCommand command) public abstract IDbDataAdapter CreateDataAdapter( string command ); public abstract IDbDataAdapter CreateDataAdapter();
	CreateNewId	Returns a new numeric PK Id public virtual int CreateNewId( string Tablename, string PkField );
	CreateParameter	Creates a new Parameter object that can be used to add parameters to a Command object. public abstract IDbDataParameter CreateParameter( string ParameterName );
	Dispose	Cleans up an open connection. public virtual void Dispose();
	EndTransaction	Ends a transaction on the current data object. Transactions can either be committed or rolled back. public virtual bool EndTransaction( bool Commit );
	ExecStoredProcedure	Executes the specified stored procedure in the specified database public abstract bool ExecStoredProcedure( string procName );
	Execute	Returns a DataSet for the specified command, database key and table name public abstract DataSet Execute( string command, string tableName ); public abstract DataSet Execute( IDbCommand SqlCommand, string tableName );
	ExecuteNonQuery	Executes the specified SQL statement and returns the number of rows affected public virtual int ExecuteNonQuery( string command ); public virtual int ExecuteNonQuery( IDbCommand SqlCommand );
	ExecuteReader	Executes the specified command and returns a DataReader object. Also returns a connection object via the connection output parameter. It is the responsibility of the caller to close the connection when finished with the DataReader public virtual IDataReader ExecuteReader( string SqlCommandString ); public virtual IDataReader ExecuteReader( IDbCommand command );
	ExecuteScalar	Executes a command and returns a single value public virtual object ExecuteScalar( string command ); public virtual object ExecuteScalar( IDbCommand SqlCommand );
	ExecXmlReader	Executes the specified command in the specified database and returns an XML Reader object public abstract XmlReader ExecXmlReader( string command );
	GenerateInsertCommand	public virtual bool GenerateInsertCommand( DataRow Row, string ServerTableName, IDbCommand& Command, string FieldsToSkip );
	GenerateUpdateCommand	public virtual bool GenerateUpdateCommand( DataRow Row, string PkField, string ServerTableName, IDbCommand& Command, string FieldsToSkip, bool WriteNonChangedFields, DataRowUpdateModes DataRowUpdateMode );
	GetEmptyDataSet	Returns an empty data set that has the table structure in it for empty rows. public abstract DataSet GetEmptyDataSet( string tableName );
	LoadDataAdapterCommands	public abstract bool LoadDataAdapterCommands( IDbCommand SelectCommand, IDbDataAdapter& Adapter );
	LoadProvider	Creates an instance of a wwData Provider object. For most types these providers are part of the framework, but for the following they call out into external assemblies that get loaded dynamically at runtime: wwDataMySql wwDataOracle wwDataVistaDb These providers require special setup. public static wwData LoadProvider( ServerTypes ServerType );
	Open	Opens a connection to the specified database public virtual bool Open();
	SaveDataRow	public bool SaveDataRow( DataRow Row, string PkField, string ServerTableName, IDbCommand& Command, string FieldsToSkip, bool WriteNonChangedFields, DataRowUpdateModes DataRowUpdateMode );
	SaveDataSet	Saves the specified DataSet and returns the number of rows updated public abstract int SaveDataSet( DataSet ds ); public abstract int SaveDataSet( DataSet ds, string Tablename, string DatabaseTableName ); public abstract int SaveDataSet( DataSet ds, string Tablename, string DatabaseTablename, IDbDataAdapter& DataAdapter );
	SetError	Sets the ErrorMessage Property public void SetError( string ErrorMessage ); public void SetError();
	TranslateParameters	Translates parameter names to match the type required for each provider as best as possible. Sql Server uses @ Fox uses ? etc. ParmChar is determined via the protected SqlParmChar. public void TranslateParameters( IDbCommand Command );
	Connection	Connection object so a connection can be held open
	ConnectionString	Connection string property
	DataSet	Dataset reference for this data member. All output goes to this dataset
	Error	Error flag after an error occurs.
	ErrorMessage	Error Message set after an error occurs.
	ExecuteWithSchema
	LastSql	This property always holds the SQL command text of the last executed query if calling Execute, ExecuteNonQuery etc.
	PrimaryKey	Primary Database key property
	Transaction	Not used at this time.

Requirements

Namespace: Westwind.BusinessObjects