ALV (ABAP List Viewer) Reports

 ALV (ABAP List Viewer) Reports are a type of interactive report in SAP ABAP that enable users to display and manipulate data in a tabular format. They are used to provide various functionalities such as sorting, filtering, and aggregating data to offer users a better understanding of the data.

There are several types of ALV reports available in ABAP such as simple, hierarchical, and block lists. Simple lists show data in a table format, hierarchical lists exhibit data in a tree-like structure, while block lists present data in a spreadsheet-like format with user-defined rows and columns.

ALV reports also offer several events that developers can utilize to customize the behavior of the report. These events include initialization, top of page, end of page, user command, and data retrieval, among others. The events allow developers to add custom functionality to the ALV report, such as adding a custom button or calculating summary values.

ALV reports offer several benefits, including a user-friendly interface that allows for the display and manipulation of large volumes of data. They also have features like sorting and filtering, which help users analyze the data easily. Additionally, ALV reports can be customized using the available events and other options to meet specific business requirements.

ALV provides a lot of inbuilt functions to our reports and some of the functions  are listed below.

• Sorting of records
• Filtering of records
• Totals and Sub-totals
• Download the report output to Excel/HTML
• Changing the order of the columns in the report
• Hide the unwanted columns  from the report

Some of the function modules used to create ALV reports are listed below

Function Module	Description
REUSE_ALV_LIST_DISPLAY	Display an ALV list
REUSE_ALV_GRID_DISPLAY	Display an ALV grid
REUSE_ALV_COMMENTARY_WRITE	Output List header information
REUSE_ALV_VARIANT_F4	Display variant selection dialog box
REUSE_ALV_VARIANT_EXISTENCE	Checks whether a variant exists
REUSE_ALV_FIELDCATALOG_MERGE	Create field catalog from dictionary structure or internal table

DATA: it_spfli TYPE TABLE OF spfli.

SELECT * FROM spfli INTO TABLE it_spfli.

CALL FUNCTION 'REUSE_ALV_GRID_DISPLAY'
  EXPORTING
    i_structure_name = 'SPFLI'
  TABLES
    t_outtab         = it_spfli.

In conclusion, ALV reports are essential interactive reports in SAP ABAP that enable users to display and manipulate data in a tabular format. There are various types of ALV reports available, and they offer events that can be used to customize their behavior. ALV reports are beneficial for displaying large volumes of data in a user-friendly manner and can be customized to meet specific business requirements.