Response Format JSON

Intro

Besides the usual terminal output, DBM-Db2 Plug-in commands can return data in the JSON format using the --rfj parameter. This feature allows processing data in automation without redundant parsing. The following article describes the structure of such response, and provides examples of how it can be used in programming languages like Python.

For more information about the Python usage, see Python samples.

Structure of the response

The following example shows the typical output of the command execution with JSON output enabled:

{
  "success": false,
  "exitCode": 1,
  "message": "Execution failed. Failure details saved to error.log\nRestart token: 840413D5D132CB8A7149C85940B7FBA4",
  "stdout": "",
  "stderr": "\u001b[31mCommand Error:\u001b[39m\n\u001b[31m\u001b[39mExecution failed. Failure details saved to error.log\nRestart token: 840413D5D132CB8A7149C85940B7FBA4\n",
  "data": {
    "files": {
      "errorFile": "error.log"
    },
    "attributes": {
      "restartToken": "840413D5D132CB8A7149C85940B7FBA4"
    }
  },
  "error": {
    "msg": "Execution failed. Failure details saved to error.log\nRestart token: 840413D5D132CB8A7149C85940B7FBA4"
  }
}

The data property contains additional information, so that you do not need to parse the message to retrieve it.

The data.files property may contain the following properties based on the output files available for a command executed:

• ddlFile
• summaryFile
• impactFile
• compareScript
• recoveryScript
• migrateScript
• errorFile

The data.attributes property may contain the following properties:

• restartToken - Available for execute commands that failed.
• hasObjectChanges - Available for the compare ddl command. false when there are 0 creates, alters, and drops - otherwise true.

The data structure is persistent across commands. If there is no data, the field remains empty:

...
"files": {},
"attributes": {}

Processing in Python

Prerequisites: Python >=3.11.0

1. JSON output always includes data, files, and attributes levels, so no verification is required.

2. Parse JSON response and get files dictionary:

   res = json.loads(response)
   files = res.get("data").get("files")

3. Get the file you need based on the command executed and outcome (success/failure):

   files.get('errorFile') # -> string relative path | None

For more information about processing JSON response in python, see Python samples.