ArcGIS 10.5 Python toolbox problem SelectLayerByAttributeERROR 000358: Invalid expression Failed to execute

Question

I am trying to create a .pyt that find and select an object in an specific layer but I have a problem. I'm working on the Desktop version 10.5 and actually the code is this one:

def getParameterInfo(self):
 """Define parameter definitions"""
 Cabina = arcpy.Parameter(
 displayName="Cabina",
 name="cab",
 datatype="string",
 parameterType="Required",
 direction="Input")
 params = [Cabina]
 return params
def isLicensed(self):
 """Set whether tool is licensed to execute."""
 return True
def updateParameters(self, parameters):
 """Modify the values and properties of parameters before internal
 validation is performed. This method is called whenever a parameter
 has been changed."""
 return
def updateMessages(self, parameters):
 """Modify the messages created by internal validation for each tool
 parameter. This method is called after internal validation."""
 return
def execute(self, parameters, messages):
 """The source code of the tool."""
 mxd = arcpy.mapping.MapDocument("CURRENT")
 lyr = arcpy.mapping.Layer(r"ESERCIZIO\ELE_ESER_Cab")
 exp = "'" + str(Cabina) + "'"
 arcpy.SelectLayerByAttribute_management(in_layer_or_view= lyr, selection_type="NEW_SELECTION", where_clause= "COD_CABINA LIKE" + exp)
 arcpy.RefreshActiveView()
 return 
 `

the problem is that continue to appear this error message: ERROR 000358: Invalid expression Failed to execute. (I'm working in an Oracle environment) Actually I tried to put a value such as exp = 'A0001' and the script work well. I read almost everything but seems like nothing works. I tried to find some documentation about how to use custom input and SQL but I did not find so much.

• Bera: Try: sql = "{0} LIKE '{1}'".format(arcpy.AddFieldDelimiters(datasource=lyr, field='COD_CABINA'), Cabina) and then arcpy.SelectLayerByAttribute_management(in_layer_or_view= lyr, selection_type="NEW_SELECTION", where_clause=sql)
• vinjazz: I tried but does not work, appear the ERROR 000358. I tried to run the script on the Python idle and there works perfectly but if i run the Toolbox something go wrong. Actually the results of .format is '"COD_CABINA" LIKE \'A540\''

Answer 1

If you change your code to this, it should work:

def getParameterInfo(self):
 """Define parameter definitions"""
 Cabina = arcpy.Parameter(
 displayName="Cabina",
 name="cab",
 datatype="string",
 parameterType="Required",
 direction="Input")
 params = [Cabina]
 return params
def isLicensed(self):
 """Set whether tool is licensed to execute."""
 return True
def updateParameters(self, parameters):
 """Modify the values and properties of parameters before internal
 validation is performed. This method is called whenever a parameter
 has been changed."""
 return
def updateMessages(self, parameters):
 """Modify the messages created by internal validation for each tool
 parameter. This method is called after internal validation."""
 return
def execute(self, parameters, messages):
 """The source code of the tool."""
 mxd = arcpy.mapping.MapDocument("CURRENT")
 lyr = arcpy.mapping.Layer(r"ESERCIZIO\ELE_ESER_Cab")
 Cabina = parameters[0].valueAsText
 exp = "{} LIKE '{}'".format(arcpy.AddFieldDelimiters(datasource=lyr, field='COD_CABINA'), Cabina)
 arcpy.SelectLayerByAttribute_management(in_layer_or_view= lyr, selection_type="NEW_SELECTION", where_clause= "COD_CABINA LIKE" + exp)
 arcpy.RefreshActiveView()
 return

The execute method doesn't know anything about the parameter you defined as Cabina, you need to define this again within this function.

Answer 2

You are defining Cabina as a Parameter then treating it as if it is a string variable when you build your expression. You need to access the Parameters value and build the sql expression from that.

• vinjazz: Thank you so much to everyone it is work! now i will go deeper in the parameter Value!