system.mes.truncateConfiguration

Sepasoft MES Module Suite

truncateConfiguration()

Overview

The truncateConfiguration script function removes all MES definition configuration data from the gateway database by truncating the MES object, link, property, artifact, change-log, and metadata tables. Call it before system.mes.importConfiguration() when you need to replace the entire MES configuration from a JSON export file. This operation is destructive and cannot be undone without a backup.

Syntax

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Python
system.mes.truncateConfiguration()

Parameters

This function takes no parameters.

Returns

Type

Description

None

The function returns void. It does not return a value.

Scope / Availability

Context

Available

Gateway scripts (MESGatewayScript)

Yes — runs truncate directly on the gateway

Client / Designer scripts (MESClientScript)

Yes — invokes the gateway through RPC

Both contexts expose the same system.mes module for configuration management.

Truncated Data

truncateConfiguration() truncates every MES table required for a full configuration reset, including:

  • MES object tables — One table per object storage type for all registered MES object types (core definition data)

  • Complex property tables — Tables backing complex properties on those object types

  • Object link tables — Definition and response MES object link tables

  • Custom property tables — Definition and response custom property tables

  • Artifacts — Stored artifact content referenced by MES objects

  • Change logs — Definition and response change-log tables

  • MES metadata — MES metadata table used by the object managers

Truncation uses database TRUNCATE operations. Tables that do not exist in the current schema are skipped without failing the call.

What this does not do

Item

Behavior

JSON export files

Files on disk (for example, MESConfig.json) are not deleted.

Non-MES tables

Only MES-managed tables collected by the gateway are truncated.

Gateway module state

Installed modules and Ignition project resources are not affected.

After truncation, system.mes.importConfiguration() can run because the object link table is empty.

Behavior

When truncateConfiguration() runs:

  1. Table discovery — The gateway builds the full set of MES definition-related table names from registered object types, complex properties, links, artifacts, change logs, and metadata.

  2. Database truncate — Each table is truncated in sequence against the MES analysis datasource.

  3. Missing tables — If a table does not exist (for example, after a schema change or partial install), that table is skipped and processing continues.

There is no gateway startup pause during truncate (unlike importConfiguration()).

Exceptions

Exception

When raised

SQLException / DBException

Database errors while truncating a table that exists and is accessible.

Exception

Other failures during the truncate transaction (wrapped from the database layer).

Example Usage

Minimal example

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Python
# Clear all MES definition data before import
system.mes.truncateConfiguration()
system.mes.importConfiguration()

Complex example

Safe migration workflow: export a backup, truncate the target, import the new configuration, and keep the backup file for rollback:

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Python
backupPath = 'C:/backups/MESConfig_before_migration.json'
deployPath = 'C:/deploy/MESConfig.json'

# Preserve current configuration to disk before wiping the database
system.mes.exportConfiguration(backupPath)

# Remove all MES definition data from the database
system.mes.truncateConfiguration()

# Load the new configuration
system.mes.importConfiguration(deployPath)

Truncate only (for example, when resetting a development gateway before manual rebuild):

Copy Code
Python
system.mes.truncateConfiguration()
print('MES definition tables cleared')

Related Functions

Module: system.mes



Sepasoft MES Module Suite