TestSchemaLock

Summary

Tests if a schema lock can be acquired for a feature class, table, or feature dataset. Tools that alter schema will require a schema lock to be placed on the input data. The Add Field tool is an example of such a tool. If the tool requires a schema lock and is unable to aquire one at the time of execution, an appropriate error message is returned. Scripts that use such tools should test if a schema lock can be acquired on the input data. The TestSchemaLock function will not actually apply a schema lock on the input data, but will return a Boolean.

Syntax

TestSchemaLock (dataset)
ParameterExplanationData Type
dataset

The input data to be tested if a schema lock can be applied.

String
Return Value
Data TypeExplanation
Boolean

Returns a Boolean indicating if a schema lock can be applied to the input dataset.

The possible Boolean values are:

  • TrueA schema lock can be applied to the dataset.
  • FalseA schema lock cannot be obtained on the dataset.

Code Sample

TestSchemaLock example

Returns a Boolean True if exclusive lock can be applied to dataset.

import arcpy

# Get the value of the input argument. 
# The argument should be a feature class. 
# 
data = arcpy.GetParameterAsText(0) 

# Test if a schema lock can be applied.
# 
lockTest = arcpy.TestSchemaLock(data) 

# If the lock can be applied, add a new field. 
# 
if lockTest:
    arcpy.AddField_management(data,"Flag","long") 
else: 
    print "Unable to acquire the necessary schema lock to add the new field"

Related Topics


10/28/2011