MaxCompute:Manage functions in a visualized manner

Background information

The following table describes the operations that you can perform on built-in functions and MaxCompute UDFs in MaxCompute Studio.

Operation	Built-in function	MaxCompute UDF	Description
Create a function			N/A.
View the syntax or code of a function			Built-in functions: You can view the syntax of built-in functions but cannot view the code of built-in functions. MaxCompute UDFs: You can view the syntax and code of MaxCompute UDFs.
Modify a function			Built-in functions: You cannot modify built-in functions. MaxCompute UDFs: If you want to modify an existing MaxCompute UDF, you must delete the UDF, redevelop the UDF, package UDF code, upload the UDF package, and create the UDF.
Delete a function			N/A.

Create a function

1. In the main menu bar of IntelliJ IDEA, choose MaxCompute > Create UDF.
2. In the Create Function dialog box, configure the parameters.
   

   Parameter	Description
   MaxCompute project	The name of the MaxCompute project in which you want to create a function.
   Function name	The name of the function that you want to create. The function name is used when you call the function in SQL statements. The function name must be unique in the MaxCompute project to which the function belongs. You can click Project Explorer in the left-side navigation pane of IntelliJ IDEA and expand the Functions folder for the MaxCompute project in the navigation tree to view the names of existing functions.
   Using resources	The resource file on which the function depends. You can select the required resource file from the resource list. If the function depends on multiple resource files, press and hold the Ctrl key, and click the required files in sequence to select them.
   Main class	The class of the function that you want to create. The class is defined in the JAR file or the PY file on which the function depends.
   Force update if already exists	If you select this option, the function that you create overwrites the existing function that has the same name in your MaxCompute project.

3. In the Create Function dialog box, click OK.
4. In the Project Explorer section, right-click the Functions folder for the MaxCompute project and select Refresh meta to refresh function information. Then, you can view the function that you created.

View the syntax or code of a function

• Built-in functions

  In the left-side navigation pane of IntelliJ IDEA, click Project Explorer. Expand the Functions folder for the MaxCompute project, and double-click the name of a built-in function in the Builtln folder to view the syntax of the function.

• MaxCompute UDFs
  In the left-side navigation pane of IntelliJ IDEA, click Project Explorer. In the Functions folder for the MaxCompute project, double-click the name of a function in the UserDefined folder to view the code of the function. You can also right-click the name of a function and select Show function detail to view the code of the function. To view the syntax of a function, you can click the name of the function in the UserDefined folder.

Delete a function

1. In the left-side navigation pane of IntelliJ IDEA, click Project Explorer. Expand the Functions folder for the MaxCompute project, right-click the name of the function that you want to delete, and then select Delete function from server.
   
2. In the Confirmation Required dialog box, click OK.
3. Right-click the Functions folder for the MaxCompute project and select Refresh meta to refresh function information. After the refresh, the deleted function is no longer displayed in the function list.