# ScanFilter (legacy)
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**Note**  
We recommend that you use the new expression parameters instead of these legacy parameters whenever possible. For more information, see [Using expressions in DynamoDB](Expressions.md). For specific information on the new parameter replacing this one, [use *FilterExpression* instead.](#FilterExpression2.instead). 

In a `Scan` operation, the legacy conditional parameter `ScanFilter` is a condition that evaluates the scan results and returns only the desired values.

**Note**  
This parameter does not support attributes of type List or Map.

If you specify more than one condition in the `ScanFilter` map, then by default all of the conditions must evaluate to true. In other words, the conditions are ANDed together. (You can use the [ConditionalOperator (legacy)](LegacyConditionalParameters.ConditionalOperator.md) parameter to OR the conditions instead. If you do this, then at least one of the conditions must evaluate to true, rather than all of them.)

Each `ScanFilter` element consists of an attribute name to compare, along with the following:
+  `AttributeValueList` - One or more values to evaluate against the supplied attribute. The number of values in the list depends on the operator specified in `ComparisonOperator` .

  For type Number, value comparisons are numeric.

  String value comparisons for greater than, equals, or less than are based on UTF-8 binary encoding. For example, `a` is greater than `A`, and `a` is greater than `B`.

  For Binary, DynamoDB treats each byte of the binary data as unsigned when it compares binary values.

  For information on specifying data types in JSON, see [DynamoDB low-level API](Programming.LowLevelAPI.md).
+  `ComparisonOperator` - A comparator for evaluating attributes. For example: equals, greater than, and less than.

  The following comparison operators are available:

   `EQ | NE | LE | LT | GE | GT | NOT_NULL | NULL | CONTAINS | NOT_CONTAINS | BEGINS_WITH | IN | BETWEEN` 

## Use *FilterExpression* instead – Example
<a name="FilterExpression2.instead"></a>

Suppose you wanted to scan the *Music* table and apply a condition to the matching items. You could use a `Scan` request with a `ScanFilter` parameter, as in this AWS CLI example:

```
aws dynamodb scan \
    --table-name Music \
    --scan-filter '{
        "Genre":{
            "AttributeValueList":[ {"S":"Rock"} ],
            "ComparisonOperator": "EQ"
        }
    }'
```

You can use a `FilterExpression` instead:

```
aws dynamodb scan \
    --table-name Music \
    --filter-expression 'Genre = :g' \
    --expression-attribute-values '{
        ":g": {"S":"Rock"} 
    }'
```