55 lines
No EOL
2 KiB
Markdown
55 lines
No EOL
2 KiB
Markdown
---
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title: "if not Insert then Modify"
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tags: ["AL","Performance"]
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categories: ["Best Practice"]
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---
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_Created by SosicStefan, Described by SosicStefan_
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## Introduction
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When handling data insertion in Business Central, a common but inefficient pattern is attempting to insert a record and modifying it if the insert fails due to duplicate keys. This approach introduces unnecessary performance overhead and should be avoided.
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{{% alert title="Note" color="info" %}}
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This pattern is only good when used on singleton table. Read more about [Singleton Table](https://alguidelines.dev/docs/navpatterns/patterns/singleton/singleton-table/).
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{{% /alert %}}
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## Why Not Use 'If Not Insert Then Modify'?
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Using the following structure:
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```al
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InitializeRecord(SomeRecord);
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if not SomeRecord.Insert() then
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SomeRecord.Modify();
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```
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Presents several issues:
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- Prevents buffered inserts: This impacts performance as batch insert optimizations are lost.
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- Generates unnecessary SQL errors: If a duplicate primary key exists, the failed insert raises an error, which Business Central must handle.
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- Slower and less efficient: Handling SQL errors is far from an optimal way to check for record existence.
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## Best Practice: Use IsEmpty
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Instead of relying on insert failures, ensure the record’s uniqueness upfront using a number series or an incremental primary key. If the data comes from an external source where duplicates might exist, use IsEmpty to check for existence.
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```AL
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InitializeRecord(SomeRecord);
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SomeRecord.SetRecFilter();
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if SomeRecord.IsEmpty() then
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SomeRecord.Insert()
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else
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SomeRecord.Modify();
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```
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## Why IsEmpty is Better
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- No SQL errors: The check is done before attempting an insert.
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- Performance improvement: Avoids unnecessary error handling and maintains buffered inserts.
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- More readable and efficient: The intent is clear—checking existence before performing actions.
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## Summary
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Avoid using if not Insert then Modify. Instead, ensure record uniqueness upfront or use IsEmpty to check existence efficiently. This leads to better performance and cleaner code. |