# DescribeMetadataModelChildren
<a name="API_DescribeMetadataModelChildren"></a>

Gets a list of child metadata models for the specified metadata model in the database hierarchy.

## Request Syntax
<a name="API_DescribeMetadataModelChildren_RequestSyntax"></a>

```
{
   "Marker": "string",
   "MaxRecords": number,
   "MigrationProjectIdentifier": "string",
   "Origin": "string",
   "SelectionRules": "string"
}
```

## Request Parameters
<a name="API_DescribeMetadataModelChildren_RequestParameters"></a>

For information about the parameters that are common to all actions, see [Common Parameters](CommonParameters.md).

The request accepts the following data in JSON format.

 ** [Marker](#API_DescribeMetadataModelChildren_RequestSyntax) **   <a name="DMS-DescribeMetadataModelChildren-request-Marker"></a>
Specifies the unique pagination token that indicates where the next page should start. If this parameter is specified, the response includes only records beyond the marker, up to the value specified by MaxRecords.  
Type: String  
Required: No

 ** [MaxRecords](#API_DescribeMetadataModelChildren_RequestSyntax) **   <a name="DMS-DescribeMetadataModelChildren-request-MaxRecords"></a>
The maximum number of metadata model children to include in the response. If more items exist than the specified MaxRecords value, a marker is included in the response so that the remaining results can be retrieved.  
Type: Integer  
Required: No

 ** [MigrationProjectIdentifier](#API_DescribeMetadataModelChildren_RequestSyntax) **   <a name="DMS-DescribeMetadataModelChildren-request-MigrationProjectIdentifier"></a>
The migration project name or Amazon Resource Name (ARN).  
Type: String  
Length Constraints: Maximum length of 255.  
Required: Yes

 ** [Origin](#API_DescribeMetadataModelChildren_RequestSyntax) **   <a name="DMS-DescribeMetadataModelChildren-request-Origin"></a>
Specifies whether to retrieve metadata from the source or target tree. Valid values: SOURCE \$1 TARGET  
Type: String  
Valid Values: `SOURCE | TARGET`   
Required: Yes

 ** [SelectionRules](#API_DescribeMetadataModelChildren_RequestSyntax) **   <a name="DMS-DescribeMetadataModelChildren-request-SelectionRules"></a>
The JSON string that specifies which metadata model's children to retrieve. Only one selection rule with "rule-action": "explicit" can be provided. For more information, see [Selection Rules](https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Tasks.CustomizingTasks.TableMapping.SelectionTransformation.Selections.html) in the DMS User Guide.  
Type: String  
Required: Yes

## Response Syntax
<a name="API_DescribeMetadataModelChildren_ResponseSyntax"></a>

```
{
   "Marker": "string",
   "MetadataModelChildren": [ 
      { 
         "MetadataModelName": "string",
         "SelectionRules": "string"
      }
   ]
}
```

## Response Elements
<a name="API_DescribeMetadataModelChildren_ResponseElements"></a>

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.

 ** [Marker](#API_DescribeMetadataModelChildren_ResponseSyntax) **   <a name="DMS-DescribeMetadataModelChildren-response-Marker"></a>
Specifies the unique pagination token that makes it possible to display the next page of metadata model children. If a marker is returned, there are more metadata model children available.  
Type: String

 ** [MetadataModelChildren](#API_DescribeMetadataModelChildren_ResponseSyntax) **   <a name="DMS-DescribeMetadataModelChildren-response-MetadataModelChildren"></a>
A list of child metadata models.  
Type: Array of [MetadataModelReference](API_MetadataModelReference.md) objects

## Errors
<a name="API_DescribeMetadataModelChildren_Errors"></a>

For information about the errors that are common to all actions, see [Common Error Types](CommonErrors.md).

 ** AccessDeniedFault **   
 AWS DMS was denied access to the endpoint. Check that the role is correctly configured.    
 ** message **   

HTTP Status Code: 400

 ** ResourceNotFoundFault **   
The resource could not be found.    
 ** message **   

HTTP Status Code: 400

## Examples
<a name="API_DescribeMetadataModelChildren_Examples"></a>

### Sample Request
<a name="API_DescribeMetadataModelChildren_Example_1"></a>

This example illustrates retrieval of child metadata models for a specified parent metadata model. The provided selection rule specifies the parent metadata model, while the origin parameter determines whether to fetch from the source or target database. The response includes a paginated list of child metadata models within the database hierarchy.

```
POST / HTTP/1.1
Host: dms.<region>.<domain>
Content-Type: application/x-amz-json-1.1
Content-Length: <PayloadSizeBytes>
Authorization: AWS4-HMAC-SHA256 Credential=<Credential>, SignedHeaders=<SignedHeaders>, Signature=<Signature>
X-Amz-Date: <Date>
X-Amz-Target: AmazonDMSv20160101.DescribeMetadataModelChildren
{
    "MigrationProjectIdentifier": "arn:aws:dms:us-east-1:012345678901:migration-project:EXAMPLEABCDEFGHIJKLMNOPQRS",
    "SelectionRules": "{\"rules\": [{\"rule-type\": \"selection\", \"rule-id\": \"1\", \"rule-name\": \"1\", \"object-locator\": {\"server-name\": \"source-database-server.us-east-1.rds.amazonaws.com\", \"category-name\": \"Databases\"}, \"rule-action\": \"explicit\"} ]}",
    "Origin": "SOURCE"
}
```

### Sample Response
<a name="API_DescribeMetadataModelChildren_Example_2"></a>

This example illustrates one usage of DescribeMetadataModelChildren.

```
HTTP/1.1 200 OK
x-amzn-RequestId: <RequestId>
Content-Type: application/x-amz-json-1.1
Content-Length: <PayloadSizeBytes>
Date: <Date>
{
    "MetadataModelChildren":[
        {
            "MetadataModelName": "database1",
            "SelectionRules": "{\"rules\": [{\"rule-type\": \"selection\", \"rule-id\": \"1\", \"rule-name\": \"1\", \"object-locator\": {\"server-name\": \"source-database-server.us-east-1.rds.amazonaws.com\", \"database-name\": \"database1\"}, \"rule-action\": \"explicit\"} ]}"
        },
        {
            "MetadataModelName": "database2",
            "SelectionRules": "{\"rules\": [{\"rule-type\": \"selection\", \"rule-id\": \"2\", \"rule-name\": \"2\", \"object-locator\": {\"server-name\": \"source-database-server.us-east-1.rds.amazonaws.com\", \"database-name\": \"database2\"}, \"rule-action\": \"explicit\"} ]}"
        }
    ]
}
```

## See Also
<a name="API_DescribeMetadataModelChildren_SeeAlso"></a>

For more information about using this API in one of the language-specific AWS SDKs, see the following:
+  [AWS Command Line Interface V2](https://docs.aws.amazon.com/goto/cli2/dms-2016-01-01/DescribeMetadataModelChildren) 
+  [AWS SDK for .NET V4](https://docs.aws.amazon.com/goto/DotNetSDKV4/dms-2016-01-01/DescribeMetadataModelChildren) 
+  [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/dms-2016-01-01/DescribeMetadataModelChildren) 
+  [AWS SDK for Go v2](https://docs.aws.amazon.com/goto/SdkForGoV2/dms-2016-01-01/DescribeMetadataModelChildren) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/dms-2016-01-01/DescribeMetadataModelChildren) 
+  [AWS SDK for JavaScript V3](https://docs.aws.amazon.com/goto/SdkForJavaScriptV3/dms-2016-01-01/DescribeMetadataModelChildren) 
+  [AWS SDK for Kotlin](https://docs.aws.amazon.com/goto/SdkForKotlin/dms-2016-01-01/DescribeMetadataModelChildren) 
+  [AWS SDK for PHP V3](https://docs.aws.amazon.com/goto/SdkForPHPV3/dms-2016-01-01/DescribeMetadataModelChildren) 
+  [AWS SDK for Python](https://docs.aws.amazon.com/goto/boto3/dms-2016-01-01/DescribeMetadataModelChildren) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/dms-2016-01-01/DescribeMetadataModelChildren)