TestSchemaLock

摘要

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.

语法

TestSchemaLock (dataset)

参数	说明	数据类型
dataset	The input data to be tested if a schema lock can be applied.	String

返回值

数据类型	说明
Boolean	Returns a Boolean indicating if a schema lock can be applied to the input dataset. The possible Boolean values are: True —A schema lock can be applied to the dataset. False —A schema lock cannot be obtained on the dataset.

代码示例

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"