What is Microsoft Access? A beginner's guide to small-scale databases available in M365 E3/E5

About this article
This article was created using an automated generation workflow utilizing generative AI. Based on current Microsoft 365 Enterprise plan information and official Microsoft documentation, Access is framed not as an "advanced version of Excel," but as a Windows-based database for structuring small-scale business data.

Verification Status: 📘 Confirmed with official Microsoft documentation, physical device verification not performed

Microsoft Access is a relational database that allows you to link multiple tables and build everything from data entry screens and searches to queries and reports within a single desktop application. "Relational" means linking separate tables, such as "Employees" and "Departments," using IDs.

Terminology primer

How do the internal components of Access connect?

flowchart LR
    U[利用者] --> F[フォーム\n入力・検索]
    F --> Q[クエリ\n抽出・集計]
    Q --> T1[(社員テーブル)]
    Q --> T2[(部署テーブル)]
    T1 --> R[レポート\n帳票・印刷]
    T2 --> R
    V[VBA\n定型処理] -.補助.-> F
    V -.補助.-> R

While Excel tends to involve repeatedly typing department names into a single sheet, Access fundamentally relies on separating "Departments" and "Employees" into distinct tables and relating them.

Positioning in M365 E3/E5

The major differences between E3 and E5 lie across the entire suite, such as security, compliance, and analytics. Choosing E5 solely to use Access is not recommended. Please re-verify actual contract SKUs and offering terms using Microsoft's official comparison table at the time of deployment.

A familiar example: Avoiding repeatedly typing department names in the employee table

Let's first consider the following two tables.

部署

- DepartmentId   ← 主キー

- DepartmentName

社員

- EmployeeId     ← 主キー

- EmployeeName

- DepartmentId   ← 部署表につなぐ値

Viewing relationships using SELECT alone

SELECT
    Employee.EmployeeName,
    Department.DepartmentName
FROM
    Department
    INNER JOIN Employee
        ON Department.DepartmentId = Employee.DepartmentId;

This is a read-only example that does not modify data.Success is achieved when employee names and their corresponding department names are displayed side by side.

Changing one thing

Add a column to search, or add a single condition to observe how the results change. It is safest not to try UPDATE or DELETE right away.

Perspectives differ across general users, administrative staff, and IT departments

Start VBA with a "reading" example

Simply displaying table names in the Immediate Window does not modify data.

Sub ListTableNames()
    Dim tdf As DAO.TableDef

    For Each tdf In CurrentDb.TableDefs
        If Left$(tdf.Name, 4) <> "MSys" Then
            Debug.Print tdf.Name
        End If
    Next tdf
End Sub

What to look for: The table names you created yourself.
Success criteria: Table names are listed, and record contents remain unchanged.
Changing one thing: TableDefs After examining this, you can use the same mindset as an entry point to learn about other objects like QueryDefs.

Do not treat Access as a "database server" simply by placing it on a shared folder

Even for small-group tools, multi-user deployment requires planning for front-end and data separation, backups, network quality, concurrent usage, and update methods. As user counts and importance increase, alternative platforms such as Dataverse, SQL-based databases, and SharePoint Lists should also be considered.

flowchart TB
    A[小規模・Windows中心\nAccessで完結] --> B{利用者や重要度が増えた?}
    B -- いいえ --> C[バックアップと保守を継続]
    B -- はい --> D[データ層を分離]
    D --> E[SQL / Dataverse等も比較]

Checklist for administrators

• Target users' Microsoft 365 licenses and Access deployment status

• Compatibility between 32-bit/64-bit versions and existing add-ins/ODBC drivers

• Handling of VBA, macros, and Trusted Locations

• Storage location and backups for .accdb files

• Front-end/back-end architecture for multi-user environments

• Ensuring user-created Access files do not become "business systems that only the creator can fix"

Official Information and Primary Sources

• Microsoft 365 Enterprise plans and pricing

• Microsoft Access help &learning

• Microsoft 365 Apps service description

The value of Access is not in having flashier features than Excel.It lies in separating data, defining relationships, and reusing the same search, data entry, and report processing routines. While convenient for small operations, if the number of users, importance, or cloud requirements increase, it is safer to re-evaluate the data foundation itself.