# DescribeMetadataModel
<a name="API_DescribeMetadataModel"></a>

Gets detailed information about the specified metadata model, including its definition and corresponding converted objects in the target database if applicable.

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

```
{
   "MigrationProjectIdentifier": "string",
   "Origin": "string",
   "SelectionRules": "string"
}
```

## Request Parameters
<a name="API_DescribeMetadataModel_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.

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

 ** [Origin](#API_DescribeMetadataModel_RequestSyntax) **   <a name="DMS-DescribeMetadataModel-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_DescribeMetadataModel_RequestSyntax) **   <a name="DMS-DescribeMetadataModel-request-SelectionRules"></a>
The JSON string that specifies which metadata model 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_DescribeMetadataModel_ResponseSyntax"></a>

```
{
   "Definition": "string",
   "MetadataModelName": "string",
   "MetadataModelType": "string",
   "TargetMetadataModels": [ 
      { 
         "MetadataModelName": "string",
         "SelectionRules": "string"
      }
   ]
}
```

## Response Elements
<a name="API_DescribeMetadataModel_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.

 ** [Definition](#API_DescribeMetadataModel_ResponseSyntax) **   <a name="DMS-DescribeMetadataModel-response-Definition"></a>
The SQL text of the metadata model. This field might not be populated for some metadata models.  
Type: String

 ** [MetadataModelName](#API_DescribeMetadataModel_ResponseSyntax) **   <a name="DMS-DescribeMetadataModel-response-MetadataModelName"></a>
The name of the metadata model.  
Type: String

 ** [MetadataModelType](#API_DescribeMetadataModel_ResponseSyntax) **   <a name="DMS-DescribeMetadataModel-response-MetadataModelType"></a>
The type of the metadata model.  
Type: String

 ** [TargetMetadataModels](#API_DescribeMetadataModel_ResponseSyntax) **   <a name="DMS-DescribeMetadataModel-response-TargetMetadataModels"></a>
A list of counterpart metadata models in the target. This field is populated only when Origin is SOURCE and after the object has been converted by DMS Schema Conversion.  
Type: Array of [MetadataModelReference](API_MetadataModelReference.md) objects

## Errors
<a name="API_DescribeMetadataModel_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_DescribeMetadataModel_Examples"></a>

### Sample Request
<a name="API_DescribeMetadataModel_Example_1"></a>

This example illustrates retrieval of information about a specified metadata model. The provided selection rule specifies which metadata model to retrieve, while the origin parameter determines whether to fetch from the source or target database. The response includes definition and corresponding converted metadata models in the target database.

```
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.DescribeMetadataModel
{
    "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\", \"database-name\": \"database1\", \"schema-name\": \"schema1\", \"table-name\": \"Table1\"}, \"rule-action\": \"explicit\"} ]}",
    "Origin": "SOURCE"
}
```

### Sample Response
<a name="API_DescribeMetadataModel_Example_2"></a>

This example illustrates one usage of DescribeMetadataModel.

```
HTTP/1.1 200 OK
x-amzn-RequestId: <RequestId>
Content-Type: application/x-amz-json-1.1
Content-Length: <PayloadSizeBytes>
Date: <Date>
{
    "MetadataModelName": "Table1",
    "MetadataModelType": "table",
    "TargetMetadataModels": [
        {
            "MetadataModelName": "table1",
            "SelectionRules": "{\"rules\": [{\"rule-type\": \"selection\", \"rule-id\": \"1\", \"rule-name\": \"1\", \"object-locator\": {\"server-name\": \"target-database-server.us-east-1.rds.amazonaws.com\", \"schema-name\": \"database1_schema1\", \"table-name\": \"table1\"}, \"rule-action\": \"explicit\"} ]}"
        }
    ],
    "Definition": "CREATE TABLE schema1.Table1 (Column1 int, Column2 int);"
}
```

## See Also
<a name="API_DescribeMetadataModel_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/DescribeMetadataModel) 
+  [AWS SDK for .NET V4](https://docs.aws.amazon.com/goto/DotNetSDKV4/dms-2016-01-01/DescribeMetadataModel) 
+  [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/dms-2016-01-01/DescribeMetadataModel) 
+  [AWS SDK for Go v2](https://docs.aws.amazon.com/goto/SdkForGoV2/dms-2016-01-01/DescribeMetadataModel) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/dms-2016-01-01/DescribeMetadataModel) 
+  [AWS SDK for JavaScript V3](https://docs.aws.amazon.com/goto/SdkForJavaScriptV3/dms-2016-01-01/DescribeMetadataModel) 
+  [AWS SDK for Kotlin](https://docs.aws.amazon.com/goto/SdkForKotlin/dms-2016-01-01/DescribeMetadataModel) 
+  [AWS SDK for PHP V3](https://docs.aws.amazon.com/goto/SdkForPHPV3/dms-2016-01-01/DescribeMetadataModel) 
+  [AWS SDK for Python](https://docs.aws.amazon.com/goto/boto3/dms-2016-01-01/DescribeMetadataModel) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/dms-2016-01-01/DescribeMetadataModel)