JSON Multimode
JSON Multimode connector provides target connections to JSON files. This connector allows you to read, write, or append data to multiple tables at one time using one map.
JavaScript Object Notation (JSON) is an open-standard, text based, language-independent data format that is generally used to store and transmit data in web applications. It was derived from JavaScript, but most modern programming languages can generate and parse JSON data format. Since JSON is much easier to parse than XML hence it is promoted as a low-overhead alternative to XML.
A JSON file uses the .json extension and its official Internet media type is "application/json".
JSON is built on two data structures:
• Objects: These are a set of name-value pairs and in most languages can be realized as an object, record, struct, dictionary, hash table, keyed list, or associative array.
• Arrays: These are an ordered list of values and in most languages can be realized as an array, vector, list, or sequence.
Connectivity Requirements
For a JSON Multimode connector:
• Target files can be stored on the local file system where Actian DataConnect is installed, and then accessed through shared storage locations.
• Target files can be stored in an external system and accessed through HTTP or HTTPS requests.
• Target connectors may be defined as a DJMessage type (djmessage:///<message name>)
Connector Parts
Connector parts are the fields you configure to connect with a data source or target.
The settings that are available depend on the connector you select.
For a list of all parts for target connectors, see
Specifying Connector, Parts, and Properties.
Connector Properties
You can specify the following target properties:
Supported Operations
JSON Multimode connector supports only Insert operations.
Supported Data Types
JSON Multimode connector supports the following data types and these data types correspond to the fields in the target data table:
• Boolean
• Byte
• Char
• Date
• Datetime
• Decimal
• Double
• Float
• Int
• Long
• Short
• String
• Time
For example, if you are appending data to an existing table, then the data type of each field uses the corresponding data type in the selected table by default.
Additional Information
Batch Response
A batch response file contains a group of entries for each connector used in a batch operation. Each action in the operation generates a batch response entry. These entries often provide detailed information, such as errors, that can be used for troubleshooting.
Example:
<BatchResponse:batchResult xmlns:BatchResponse="http://www.actian.com/BatchResponse">
<BatchResponse:results>
</BatchResponse:results>
<BatchResponse:componentInfo>
<BatchResponse:returnCode>0</BatchResponse:returnCode>
<BatchResponse:componentName>JSON-DMS</BatchResponse:componentName>
</BatchResponse:componentInfo>
</BatchResponse:batchResult>
Schema Considerations
The JSON Multimode connector differs from other Multimode connectors as follows:
• If the target file exists, the UI connects using a source JSON connection and then the schema is copied to the target. The schema is built from the data, which may be a subset of the actual schema.
• If the target file does not exist, then a basic schema is created based on the source. The schema can be edited in advance mode or an external schema can be configured.
Custom JSON
If the __._JSON_INPUT (JSON_INPUT field) is mapped on the target side, the field is a string field and the connector treats the mapped string as a Custom JSON.
The JSON_INPUT field provides a way to add a custom output structure to a target record. When discovering a JSON schema, the JSON_INPUT field is automatically created as the first field in a record. If the JSON_INPUT field is empty in the target then it will be ignored, however, if it has a value, then the processing of subsequent fields in the record is ignored. Therefore, if used, the JSON_INPUT field must be the first field listed for the record type.
WARNING! The connector may output invalid JSON if you do not validate the JSON when mapping the Custom JSON field. This is because the connector does not validate the data in the JSON_INPUT field.
There are some considerations you need to take into account when using the JSON_INPUT field:
• If the JSON_INPUT field is mapped on a record, all child records of this record will be skipped, even if they are mapped. The remaining fields on the record will be skipped as well (even if they are mapped).
• Since the JSON_INPUT field is a string, you must escape any string contained in the custom JSON data field, as shown in the following example:
User input to JSON_INPUT field:"{""Field"":""Value"", ""Field2"":12}""
Connector output for JSON_INPUT:{"Field":"Value", "Field2":12}
In this example, Field, Value, and Field2 are strings. The value of 12 is a number.
• If a schema contains an empty array [] or empty object {}, __._JSON_INPUT can be set to [] or {} respectively, to correctly output the record.
• Another use would be to add content based on an EZscript expression. For example, creating a name:value pair with the processing date:
="""theDate"" : """ & Date() & """"
In this example, field names and values are in double quotes to escape strings.