Portable Executable

Introduction

Portable Executable is a file format for executables in Windows Operating Systems. It would encapsulates the required information for the Windows OS loaders.

Dynamic-link Library (DLL)

It is Microsoft’s implementation of the shared library. The file format of DLL is the same as the Window EXE files.

Excel VBA – Oracle Database Connection with ADO

ActiveX Data Object (ADO)

ADO is Microsoft’s Component Object Model (COM) objects for accessing data source.

ADO Object Model

IC46663

Example

Source Code

Sub main()
 Dim objConnection As New ADODB.Connection
 Dim Recordset As New ADODB.Recordset
 
 strcon = "Provider=MSDAORA;Data Source=<IP>:<PORT>/<SID>;User Id=<USER NAME>;Password=<PASSWOR>;"
 objConnection.ConnectionTimeout = 0
 objConnection.Open (strcon)
 
 
 objConnection.CommandTimeout = 15
 
 
 sqlStr = "select * from USER_TABLES"
 
 Dim cmd1 As New ADODB.Command
 cmd1.ActiveConnection = objConnection
 cmd1.CommandText = sqlStr
 Set Recordset = cmd1.Execute

 
 objConnection.Close
 
End Sub

 

Points to Note

  • OLE DB is a way to access data store while ADO is a way to access data.

Reference:

https://support.microsoft.com/en-us/kb/194973

 

 

 

 

 

OLE DB, ADO, ODBC

Object Linked and Embedding, Database (OLE DB)

It is an API for access various datasource in a uniform manner.

ole db

ActiveX Data Object (ADO)

It is a middleware layer for accessing and manipulate data through OLE DB Provider.

ADO

Reference:

https://msdn.microsoft.com/en-us/library/ms675532(v=vs.85).aspx

https://en.wikipedia.org/wiki/ActiveX_Data_Objects

Open Database Connectivity (ODBC)

It is a api for accessing relational database management system (RDBMS).

The task is accomplished by ODBC Driver.

odbc