[Definitive Guide] What Is Oracle OO4O (Oracle Objects for OLE)? End of Support and Migration to ADO

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■ What Is OO4O (Oracle Objects for OLE)?

Oracle Objects for OLE (OO4O) is a COM-based (Component Object Model) API built on Microsoft’s OLE (Object Linking and Embedding) technology.
It was primarily used to connect and interact with Oracle databases from VB6, VBA (Access, Excel), and similar environments.

▼ Key Features

  • Windows-only (primarily for 32-bit environments)
  • Optimized object model for Oracle (e.g., OraSession, OraDatabase)
  • Easy execution of PL/SQL blocks
  • In some cases, faster than ADO (especially with older Oracle versions)

■ Supported Oracle Versions

Oracle Version Compatibility
Oracle 8i Fully supported
Oracle 9i Fully supported
Oracle 10g Supported
Oracle 11g Not recommended but included (32-bit only)
Oracle 12c+ Not supported (fully deprecated)

Oracle 11g (32-bit) is generally considered the final version compatible with OO4O.

■ Why Was OO4O Deprecated?

  • No support for 64-bit environments (32-bit only)
  • Based on outdated COM/OLE/ActiveX technology with security risks
  • Shift in Microsoft’s VB6/VBA strategy
  • Oracle now recommends modern APIs such as ODP.NET, ODBC, ADO.NET, and JDBC

■ How to Migrate from OO4O to ADO

Code using OO4O should generally be migrated to use ADO (ActiveX Data Objects) with Oracle Provider for OLE DB.

▼ OO4O Connection Example

Dim OraSession As Object
Dim OraDatabase As Object

Set OraSession = CreateObject("OracleInProcServer.XOraSession")
Set OraDatabase = OraSession.OpenDatabase("ORCL", "user/password", 0)

▼ ADO Connection Example (using Microsoft OLE DB Provider for Oracle)

Dim conn As Object
Set conn = CreateObject("ADODB.Connection")

conn.Open "Provider=MSDAORA;Data Source=ORCL;User ID=user;Password=password;"

Note: Microsoft’s MSDAORA provider is deprecated. Oracle recommends using the following instead: 

Provider=OraOLEDB.Oracle;

▼ SELECT Statement Example (ADO)

Dim rs As Object
Set rs = CreateObject("ADODB.Recordset")

rs.Open "SELECT * FROM employees", conn
Do Until rs.EOF
    Debug.Print rs.Fields(0).Value
    rs.MoveNext
Loop
rs.Close

■ Key Points When Migrating to ADO

  • All OO4O-specific objects (e.g., OraDatabase) must be replaced with ADO equivalents
  • Handling arrays and calling PL/SQL procedures differ from OO4O
  • Oracle Provider requires correct installation of the Oracle Client

■ Summary

Item OO4O ADO + Oracle Provider
Support Up to Oracle 11g (32-bit) Recommended for later versions
Technology Base COM/OLE COM (ADO)
Recommendation × (Deprecated) ○ (Migration recommended)

OO4O was historically important, but migration is now essential.
For better maintainability and security, early migration to ADO or ODP.NET is strongly recommended.

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■ Related Keywords

  • Oracle OO4O deprecated
  • OO4O Oracle 11g
  • Oracle VBA connection method
  • Oracle OLEDB ADO migration
  • Access VBA Oracle connection 2025