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How to Combine Multiple Conditions in AWS SDK for Go DynamoDB FilterExpression?

Barbara Streisand
Barbara StreisandOriginal
2024-10-31 23:42:29626browse

How to Combine Multiple Conditions in AWS SDK for Go DynamoDB FilterExpression?

Multiple Conditions in AWS SDK for Go DynamoDB FilterExpression Using Expression Builder

Developers often encounter the need to filter DynamoDB scans based on multiple conditions. The expression builder provided by the AWS SDK for Go offers a convenient way to define these conditions. However, it's important to understand how to add multiple conditions effectively.

Initial Misconception

Contrary to initial assumptions, attempting to add multiple conditions using WithCondition will overwrite previous conditions. This can be frustrating when desiring a compound filtering mechanism.

Correct Approach with And, Or, and Not

The solution lies in leveraging the And, Or, and Not methods of the ConditionBuilder struct. By chaining these methods, you can create complex filtering expressions involving multiple conditions.

For instance, to filter based on both foo = 5 and bar = 6, you can write the following code:

<code class="go">cond1 := expression.Name("foo").Equal(expression.Value(5))
cond2 := expression.Name("bar").Equal(expression.Value(6))
expr, err := expression.NewBuilder().
    WithCondition(cond1.And(cond2)).
    Build()</code>

Conclusion

By utilizing the And, Or, and Not methods, you can effectively add multiple conditions to your DynamoDB FilterExpression using the Expression Builder in AWS SDK for Go. This allows for more flexibility and control in filtering your table data. Remember to refer to the documentation for further details and examples.

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