Help Center/ Distributed Database Middleware/ API Reference/ APIs (Recommended)/ Schemas/ Querying Schemas
Updated on 2026-06-02 GMT+08:00
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Querying Schemas

Function

This API is used to query schemas of a DDM instance.

Constraints

None

URI

GET /v1/{project_id}/instances/{instance_id}/databases?offset={offset}&limit={limit}

Table 1 URI parameters

Parameter

Mandatory

Type

Description

project_id

Yes

String

Project ID of a tenant in a region

To obtain this value, see Obtaining a Project ID.

instance_id

Yes

String

DDM instance ID
Table 2 Query parameters

Parameter

Mandatory

Type

Description

offset

No

Integer

Index offset.

The query starts from the next piece of data indexed by this parameter. The value is 0 by default.

The value must be a non-negative number.

limit

No

Integer

Maximum schemas to be queried.

Value range: 1 to 128.

If the parameter value is not specified, 128 nodes are queried by default.

Request Parameters

Table 3 Request header parameters

Parameter

Mandatory

Type

Description

X-Auth-Token

Yes

String

User token

You can obtain the token by calling the IAM API used to obtain a user token.

Response Parameters

Status code: 200

Table 4 Response body parameters

Parameter

Type

Description

databases

Array of GetDatabaseInfo objects

Schema information

total

Integer

Total records
Table 5 GetDatabaseInfo

Parameter

Type

Description

name

String

Schema name

shard_mode

String

Sharding mode of the schema

  • cluster: indicates that the schema is in sharded mode.
  • single: indicates that the schema is in unsharded mode.

shard_number

Integer

Number of shards in the same working mode

status

String

Schema status

created

Long

Time when the schema was created

used_rds

Array of GetDatabaseUsedRds objects

RDS instances associated with the schema

shard_unit

Integer

Number of shards per RDS instance
Table 6 GetDatabaseUsedRds

Parameter

Type

Description

id

String

Node ID of the associated RDS instance

name

String

Name of the associated RDS instance

status

String

Status of the associated RDS instance

error_msg

String

Response message. This parameter is not returned if no abnormality occurs.

Status code: 400

Table 7 Response body parameters

Parameter

Type

Description

errCode

String

Service error code

externalMessage

String

Error message

Status code: 500

Table 8 Response body parameters

Parameter

Type

Description

errCode

String

Service error code

externalMessage

String

Error message

Example Request

Querying schemas

GET https://{endpoint}/v1/{project_id}/instances/{instance_id}/databases?offset={offset}&limit={limit}

Example Response

Status code: 200

OK

{
  "databases" : [ {
    "status" : "RUNNING",
    "created" : 1642063713625,
    "name" : "mytestdb170",
    "shard_mode" : "cluster",
    "shard_number" : 8,
    "shard_unit" : 8,
    "used_rds" : [ {
      "id" : "c6f68fed9e74478c8679479a07d7d568in01",
      "status" : "normal",
      "name" : "rds-test"
    } ]
  } ],
  "total" : 172
}

Status code: 400

Bad request

{
  "externalMessage" : "Parameter error.",
  "errCode" : "DBS.280001"
}

Status code: 500

Server error

{
  "externalMessage" : "Server failure.",
  "errCode" : "DBS.200412"
}

Status Codes

Status Code

Description

200

OK

400

Bad request

500

Server error

Error Codes

For details, see Error Codes.

Parent topic: Schemas