This field is responsible for setting up columns in proper order while displaying the grid without using of saved layout. It may be useful if you don’t allow your users to save their own or global grid layouts, so then the grid looks always the same for them. Personally I leave this almost always empty, but if needed just simply use INTEGER values to setup correct sorting. The demo program that can be found in Figure 11 can be used to see the difference between standard sorting and own one. 

Figure 11 ZDEMO_AIN_CL05 COL_POS

Own sorting firstly takes care about positions of columns from field catalog, then it displays the rest. If I would not pass parameter I_STRUCTURE_NAME then only this fields which are in table FCAT would appear on the screen.

Figure 12 ZDEMO_AIN_CL05 Own Sequence

Figure 13  ZDEMO_AIN_CL05 Standard sequence

This field is one of the basic ones in field catalog. It contains the fieldname of internal table that will be used in our grid. Although LVC_T_FCAT is standard table, then this field should be treated as key field, as in fact it is. If you fill this field manually, then please remember to put the field names in UPPER CASE.

You have to also remember that if field catalog will not contain all fields from the table and you don’t pass the dictionary name to parameter I_STRUCTURE_NAME of SET_TABLE_FOR_FIRST_DISPLAY method, then it will only display this fields, which are in field catalog. 

In Figure 14 you can see that, the field catalog is created manually with only field names inside. I also do not pass I_STRUCTURE_NAME parameter, so then only field catalog will be used to prepare the display of internal table. As I haven’t filled anything in there beside the name of the field, the output will be really poor. We will have data displayed in our grid, but without any descriptions in header, without any formatting or search helps.

Figure 14 ZDEMO_AIN_CL06 Field catalog with only field names

Figure 15 ZDEMO_AI_CL06 Results

The name of this field suggest to put here an internal table name, but it seems that it has no function at all. When SAP fills field catalog automatically, then value of this field is set to ‘1’. You can completely omit this field, as if you fill it then nothing will happen, even if you use different values for each field in field catalog.

Figure 16 ZDEMO_AIN_CL07 Tabname filled

When you have a field that contains an amount, for example net value of an sales order, then in order to show it correctly in the grid you should fill or this field with an value of currency key (one of entries from TCURC table). You can leave this field of course empty and in many case you will, especially if you use CFIELDNAME instead. 

In many situations changing the of currency here will not make difference to the output, but there are some exceptions, for example JPY (Japanese Yen) don’t have decimal places. Figure 17 displays value of 42 294 whereas the internal value of field is 422,94. If we use ZDEMO_AIN_CL08 program with USD currency then as you seen in Figure 18, the value shown is equal to 422,94. Both outputs are correct as long as the currency of the corresponding line is the same as in field catalog.

Figure 17 ZDEMO_AIN_CL08 Output using JPY

Figure 18 ZDEMO_AIN_CL08 Output using USD

That’s why the CFIELDNAME is very handy to use in that situations where you have different currencies for different rows.