Best Practices for Table Methods in Dynamics 365 Finance and Operations

 

📘 Introduction

In Microsoft Dynamics 365 Finance and Operations (D365FO), table methods are essential for encapsulating logic that relates to specific database tables. This article explains the two main types of table methods—Application-defined and System-defined—and shares best practices for writing and maintaining them.

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🧠 Types of Table Methods

1. Application-Defined Methods

These are custom methods written by developers specifically for a particular table. These methods are typically created to:

• Search for records

• Check existence

• Enforce business logic

2. System-Defined Methods

These are automatically available on every table and are inherited from the base xRecord class. Examples include:

• insert()

• update()

• delete()

• doInsert()

• doUpdate()

• doDelete()

• validateWrite()

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🧾 Best Practices for Application-Defined Table Methods

✅ Use Table and Field Properties Whenever Possible

Avoid writing code if the same functionality can be achieved by setting table or field properties. Examples:

• AllowEdit

• Visible

• Mandatory

• DefaultValue

✅ Only Create Methods Relevant to the Table

Each method should serve a specific purpose that’s logically tied to the table. Avoid putting unrelated logic in table methods.

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📌 Recommended Static Methods for Tables with Unique Keys

If your table has a unique key, it is considered best practice to implement the following static methods:

Method	Description
static find(...)	Returns a single record based on a unique identifier.
static exist(...)	Returns a boolean indicating whether the record exists.
static checkExist(...)	Throws an error if the record does not exist.
static txtNotExist(...)	Returns a descriptive string if the record is missing.

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💡 Method Behavior Across Tiers

By default, these methods execute on both client and server tiers. You can explicitly define them with client server, like so:

x++
client server static CustTable find(AccountNum _accountNum, boolean _forUpdate = false)
{
    return CustTable::findRecId(_accountNum, _forUpdate);
}

⚠️ Do not specify only one tier (client or server) unless absolutely necessary. This ensures flexibility and prevents tier violation errors.

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✅ Summary

Practice	Recommendation
Use properties	Prefer built-in properties over custom code
Method purpose	Keep logic relevant to the table
Static methods	Implement find, exist, checkExist, txtNotExist
Tier declaration	Use client server instead of a single tier

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📌 Final Note

While D365FO won't throw best practice errors for missing find() or exist() methods, including them improves code readability, reusability, and aligns with established standards—especially important in large implementations or ISV solutions.