# Differences between a relational (SQL) database and DynamoDB when deleting data from a table
Deleting data from a table

In SQL, the `DELETE` statement removes one or more rows from a table. Amazon DynamoDB uses the `DeleteItem` operation to delete one item at a time.

**Topics**
+ [

## Deleting data from a table with SQL
](#SQLtoNoSQL.DeleteData.SQL)
+ [

## Deleting data from a table in DynamoDB
](#SQLtoNoSQL.DeleteData.DynamoDB)

## Deleting data from a table with SQL


In SQL, you use the `DELETE` statement to delete one or more rows. The `WHERE` clause determines the rows that you want to modify. The following is an example.

```
DELETE FROM Music
WHERE Artist = 'The Acme Band' AND SongTitle = 'Look Out, World';
```

You can modify the `WHERE` clause to delete multiple rows. For example, you could delete all of the songs by a particular artist, as shown in the following example.

```
DELETE FROM Music WHERE Artist = 'The Acme Band'
```

## Deleting data from a table in DynamoDB


In DynamoDB, you can use either the DynamoDB API or [PartiQL](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ql-reference.html) (a SQL-compatible query language) to delete a single item. If you want to modify multiple items, you must use multiple operations.

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#### [ DynamoDB API ]

With the DynamoDB API, you use the `DeleteItem` operation to delete data from a table, one item at a time. You must specify the item's primary key values.

```
{
    TableName: "Music",
    Key: {
        Artist: "The Acme Band",
        SongTitle: "Look Out, World"
    }
}
```

**Note**  
In addition to `DeleteItem`, Amazon DynamoDB supports a `BatchWriteItem` operation for deleting multiple items at the same time.

`DeleteItem` supports *conditional writes*, where the operation succeeds only if a specific `ConditionExpression` evaluates to true. For example, the following `DeleteItem` operation deletes the item only if it has a *RecordLabel* attribute.

```
{
    TableName: "Music",
    Key: {
        Artist: "The Acme Band",
        SongTitle: "Look Out, World"
    },
   ConditionExpression: "attribute_exists(RecordLabel)"
}
```

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#### [ PartiQL for DynamoDB ]

With PartiQL, you use the `Delete` statement through the `ExecuteStatement` operation to delete data from a table, one item at a time. You must specify the item's primary key values.

The primary key for this table consists of *Artist* and *SongTitle*. You must specify values for these attributes.

```
DELETE FROM Music
WHERE Artist = 'Acme Band' AND SongTitle = 'PartiQL Rocks'
```

You can also specify additional conditions for the operation. The following `DELETE` operation only deletes the item if it has more than 11 *Awards*.

```
DELETE FROM Music
WHERE Artist = 'Acme Band' AND SongTitle = 'PartiQL Rocks' AND Awards > 11
```

**Note**  
For code examples using `DELETE` and `ExecuteStatement`, see [PartiQL delete statements for DynamoDB](ql-reference.delete.md).

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