Function operations

• Function names must be unique. Each function name can be used only once.
• UDFs cannot overwrite built-in functions of MaxCompute. Only the project owner is allowed to overwrite built-in functions with UDFs. If you use a UDF that overwrites a built-in function, warning information is displayed in Summary of the Logview of your job after the SQL statement is executed.

create function <function_name> as <'package_to_class'> using <'resource_list'>;

• function_name: required. The name of the UDF that you want to create.
• package_to_class: required. The name of the package. It must be enclosed in single quotation marks (').
  • For a Java UDF, specify this name as a fully qualified class name from the top-level package name to the UDF class name.
  • For a Python UDF, specify this name in the format of Python script name.Class name.
• resource_list: required. The list of resources used by the UDF.
  • The resource list must include the resource that contains UDF code. Make sure that this resource is uploaded to MaxCompute.
  • If the code calls the Distributed Cache API to read resource files, this resource list must also contain the list of resource files that are read by the UDF.
  • The resource list consists of multiple resource names and must be enclosed in single quotation marks ('). The resource names are separated by commas (,).
  • To specify the project that contains the resource, write the expression in the <project_name>/resources/<resource_name> format.

• Example 1: Create the my_lower function. In this example, the Java UDF class org.alidata.odps.udf.examples.Lower is in my_lower.jar.

  create function my_lower as 'org.alidata.odps.udf.examples.Lower' using 'my_lower.jar';

• Example 2: Create the my_lower function. In this example, the Python UDF class MyLower is in the pyudf_test.py script of the test_project project.

  create function my_lower as 'pyudf_test.MyLower' using 'test_project/resources/pyudf_test.py';

• Example 3: Create the test_udtf function. In this example, the Java UDF class com.aliyun.odps.examples.udf.UDTFResource is in udtfexample1.jar. The function depends on the file resource file_resource.txt, the table resource table_resource1, and the archive resource test_archive.zip.

  create function test_udtf as 'com.aliyun.odps.examples.udf.UDTFResource' using 'udtfexample1.jar, file_resource.txt, table_resource1, test_archive.zip';

drop function <function_name>;

function_name: required. The name of an existing function.

-- Delete the my_lower function.
drop function my_lower;

desc function <function_name>;

function_name: required. The name of an existing function.

-- View the information of the my_lower function.
desc function my_lower;

Name                                    my_lower
Owner                                   ALIYUN$****
Created Time                            2020-06-18 15:50:19
Class                                   org.alidata.odps.udf.examples.Lower
Resources                               project_name/my_lower.jar

list functions [-p <project_name>];

project_name: optional. The name of a MaxCompute project.

list functions;

Name              Owner                         Create Time           Class                             Resources
0 functions