DATATYPE field has small influence on the way the column is displayed. You can omit this field and then ALV grid will automatically fill this field and additionally JUST, OUTPUTLEN, INTTYPE, INTLEN and DD_OUTLEN on a base of the type of the output table field.  

But if you decide to fill it, then on a base of DATATYPE you’ll notice different justification or output length. But still all checks of the data entered in edit mode will be done on a base of the real data type of the linked internal table field.

Possible data types form system NW 7.52 SP04 can be found bellow.

Table 2 Possible data types in NW 7.52 SP04

The main functionality of the ROLLNAME is to provide a data element that will be responsible for showing F1 help on the grid cell. If in data element the documentation is available, then it will be shown. If not, or if the ROLLNAME will be empty, you’ll receive the message “No documentation available” when you’ll press F1 on a grid cell.

Figure 84 Result of F1 with empty ROLLNAME

In the demo program I’ve used data element S_CONN_ID to show you how does it work.

Figure 85 ZDEMO_AIN_CL35 Selection Screen

On the first sight you can notice that if you’ll use ROLLNAME, then the column description, tooltip and column short and long texts are taken from the data element.

Figure 86 ZDEMO_AIN_CL35 Results with ROLLNAME

Figure 87 ZDEMO_AIN_CL35 Change layout screen

Additionally to this, the main behaviour is also there. F1 shows the documentation from the data element.

Figure 88 ZDEMO_AIN_CL35 F1 Help for CONNID column

Just to show you where this information comes from, here it comes the view from SE11 and data element S_CONN_ID.

Figure 89 SE11 for S_CONN_ID

TOOLTIP, as in any other places in on your PC, is responsible to show short info about the column when you hover your mouse over the column header. It’s very useful when you have a lots of fields in you grid and you’re optimizing the width of the column by minimizing the description of the column itself. It is common behaviour for example for checkboxes or for icon columns. In this case the Tooltip is very helpful for explaining the user the meaning of the column.

Figure 81 ZDEMO_AIN_CL34 Tooltip of an column

Additionally if you’ll not use SELTEXT field, then the value from TOOLTIP will be used as description used to describe the column in the change layout screen.

Figure 82 ZDEMO_AIN_CL34 ABAP Code for Tooltip

Figure 83 ZDEMO_AIN_CL34 Change layout screen

SELTEXT is one of the fields that are linked to the texts of the grid columns. This particular one is responsible for displaying the name of the column in the change/display of layout popup.

Figure 79 ZDEMO_AIN_CL33 Column description in the layout popup

In case the TOOLTIP field is empty, the value from SELTEXT will be also used as tooltip and will appear when you hover the mouse over the column in the grid.

Figure 80 ZDEMO_AIN_CL33 SELTEXT as a TOOLTIP

Conversion Exit was already mentioned while describing the EDIT_MASK field, but here it is called in a bit different way. Before saying how, it is important to understand the conversion exits. They are no more and no less than a function modules that helps to represent the internal values into understandable or more readable values. An basic example is field MATNR which is 18 characters long in ECC and 40 in S/4 HANA, and if it contains only numbers (for example 123),  then the internal value is stored with leading zeros, for example 000000000000000123 in ECC system. As you can imagine reading 123 is easier than 000000000000000123, that’s why field MATNR uses conversion exit ALPHA which deletes the leading zeros in case there are only numbers inside the fields.

There are many standard conversion exits, you can find the by searching of FM that begins with CONVERSION_EXIT_*. You’ll notice that after the second underscore there is a five characters name of the conversion exit, and then _INPUT or _OUTPUT. _INPUT and _OUTPUT describes if the FM is responsible for converting external value into internal (INPUT) or form internal value into external (OUTPUT).

Figure 75 Search of Conversion Exits

In the example program ZDEMO_AIN_CL32 I’ve setup column CONNID to use conversion exit NUMCV. As you see you don’t put the full name of the FM into the CONVEXIT field, it only assumes to get the 5 characters describing the name of the exit. It knows automatically that for output it needs to use CONVERSION_EXIT_NUMCV_OUPUT and for input (in case of editable fields) CONVERSION_EXIT_NUMCV_INPUT.

Figure 76 ZDEMO_AIN_CL32 Conversion Exit NUMCV for field CONNID

When you run the program you can select if you want to see the CONNID with or without conversion exit. In case you want to see it with it, the values of the field will be represented with leading zeros. You may be wondering why it is opposite when you don’t use conversion exit as the internal value in the database is with leading zeros. For some of the types (like NUMC) the output is always done without leading zeros, so if you want to explicitly set to see them, you need to use conversion exits.

Figure 77 ZDEMO_AIN_CL32 Output with Conversion Exit NUMCV

The next figure shows the output without the conversion exit.

Figure 78 ZDEMO_AIN_CL32 Output without Conversion Exit NUMCV

Technical field allows you to do similar thing as NO_OUT, you can hide the field on the output, the difference is that, users are not able to unhide this field. As NO_OUT, in order that TECH field work, you need to set its value to ‘X’.

Figure 70 ZDEMO_AIN_CL30 Setting of Field as Technical

Such setting is very helpful when you have to store some additional values in the internal table that supposed to be displayed, but you do not want to display them. Such field can be used for example during the event handling or displaying totals and subtotals.

It can also be used with the AUTHORITY-CHECK, just assume that you want to display one or two columns only to specific users that have the authorization for it ( like simple sales margin). After checking the authorization, you can setup the field as technical if user doesn’t have authorization to see it.

Figure 71 ZDEMO_AIN_CL30 Technical fields are not visible

NO_OUT is useful when you want to hide the field on the output, but still allow users to unhide it on demand. As lots of fields from field catalog, it can be filled with ‘X’ or space (default).

If you set it to ‘X’, then as long as user will not unhide it and save it to the ALV variant, it will not be visible on the screen. But as said before it can be unhide using the display options.

Figure 68 ZDEMO_AIN_CL29 hiding of columns

In this case I’ve also filled the REPTEXT column, in order to show you that it is possible to move the columns to display. If I wouldn’t do that, then description would be empty.

Figure 69 ZDEMO_AIN_CL29 Change of the layout

As you can imagine from the name, NO_SUM does mostly opposite what DO_SUM, but in more secure way. If you don’t want that the field is allowed to be summarized, then set the value of this field to ‘X’. It will not only not show the sum, but also it will forbid to set it the GUI.

Figure 66 ZDEMO_AIN_CL28 DO_SUM for DISTANCE field

Once user will try to summarize the values of this column, he will get the message “Desired operation cannot be performed for column”.

Figure 67 ZDEMO_AIN_CL28 Message at try of making sum of DISTANCE field

DO_SUM is very helpful when you want to assure that some of the numeric fields are summarized directly after the output, without interaction from the user side. In order to do so, just put the ‘X’ or ABAP_TRUE into the value of this field in the field catalog.

One remark, if you’re adding this setting to value or quantity field, make sure that you also fill the QFIELDNAME or CFIELDNAME to have the sum of each unit or currency separately. In other case the values will be summarized without taking in consideration differences in the units.

Figure 64 ZDEMO_AIN_CL27 DO_SUM set for DISTANCE field

Figure 65 ZDEMO_AIN_CL27 Results with the DO_SUM and QFIELDNAME filled

FIX_COLUMN can be useful when you have a lots of fields in the field catalog and you want to make sure that some of the key fields are always visible, for example sales order number and position or posting document number. When you setup the value of this field to ‘X’, then the column(s) will be always visible. While scrolling the fields after the last field which has this flag will be moving left or right.

It is important to remember that it is not enough to say that for example 3^rd column should be fixed. You must set this flag to all fields up to the last one, that should be fixed in order this setting work correctly.

Figure 61 ZDEMO_AIN_CL26 Setting FIX_COLUMN

Just make sure that you do not setup too much field like this, as it can happen that on small screens users will only see selected fields and nothing more.

When you’ll run the ZDEMO_AIN_CL26 program, you can see the behaviour of the FIX_COLUMN field. If you have wide screen, please resize the SAP GUI window, so the full grid is not visible.

Figure 62 ZDEMO_AIN_CL26 Field catalog fixed on AIRPFROM field

Figure 63 ZDEMO_AIN_CL26 Field catalog fixed on AIRPFROM field