Table has multiple records in which mobileNumber column is in only few records . I need to get those records only

Question

Table has multiple records in which mobileNumber column is in only few records . I need to get those records only.

By this query i am getting all records.

$request = [
    'TableName' => 'tbl_camp',
    'ExpressionAttributeNames' => [
        '#mobileNumber' => 'mobileNumber'
    ],
    'ExpressionAttributeValues' => [
        ':val1' => ['S' => 'NULL']
    ],
    'FilterExpression' => '#mobileNumber <> :val1',
];

Answer 1

You can use attribute_exists() function to filter out items with whether certain attribute present.

Your query becomes something like this:

$request = [
    'TableName' => 'tbl_camp',
    'ExpressionAttributeNames' => [
        '#mobileNumber' => 'mobileNumber'
    ],
    'ExpressionAttributeValues' => [
        ':val1' => ['S' => 'NULL']
    ],
    'FilterExpression' => 'attribute_exists(#mobileNumber)',
];

You can read about this at AWS documentation.