函数组说明：ABAP/4 词典的界面（应翻译为接口）；
这个函数组可以用来操作 ABAP 字典中的数据对象，可以经常使用后缀为 GET 的，其它的慎用。
DDIF_DOMA_ACTIVATE DD：激活域的接口
DDIF_DOMA_GET DD: Interface for reading a domain from the ABAP Dictionary
DDIF_DOMA_PUT DD：将域写入 ABAP 字典的接口
DDIF_DTEL_ACTIVATE DD: Interface to activate a data element
DDIF_DTEL_GET DD: 从 ABAP/4 词典读取数据元素的接口
DDIF_DTEL_PUT DD: Interface for writing a data element to the ABAP Dictionary
DDIF_ENQU_ACTIVATE DD:激活锁定的对象的界面
DDIF_ENQU_GET DD: Interface for reading a lock object from the ABAP Dictionary
DDIF_ENQU_PUT DD: Interface for writing a lock object to the ABAP Dictionary
DDIF_INDX_ACTIVATE DD：激活索引的接口
DDIF_INDX_GET DD: Interface for reading an index from the ABAP Dictionary
DDIF_INDX_PUT DD: Interface to write an index to the ABAP Dictionary
DDIF_OBJECT_DELETE DD: Interface for Deleting an ABAP Dictionary Object
DDIF_OBJECT_RESET 重新设置 DD 对象（例如删除新的或修订版本）
DDIF_SHLP_ACTIVATE DD: interface for activating a search help
DDIF_SHLP_GET DD: Interface to read a search help from the ABAP Dictionary
DDIF_SHLP_PUT DD: Interface to write a search help in the ABAP Dictionary
DDIF_STATE_GET DD: Interface for Determining the Status of an ABAP Dictionary Object
DDIF_TABL_ACTIVATE DD：激活表格的接口
DDIF_TABL_GET DD：从 ABAP 字典读取表格的界面
DDIF_TABL_PUT DD：将表格写入 ABAP 字典的接口
DDIF_TABT_ACTIVATE DD: Interface for activating the technical settings of a table
DDIF_TABT_GET DD：从 ABAP 字典读取技术设置的界面
DDIF_TABT_PUT DD: 将技术设置写入 ABAP 字典的界面
DDIF_TTYP_ACTIVATE DD: Interface for Activating a Table Type
DDIF_TTYP_GET DD: Interface for Reading a Table Type from the ABAP Dictionary
DDIF_TTYP_PUT DD: Interface for Writing a Table Type to the ABAP Dictionary
DDIF_TYPEINFO_GET DD: Get Information on a Type Defined in the ABAP Dictionary
DDIF_VIET_GET DD: Interface for reading view techn. settings from the ABAP Dictionary
DDIF_VIET_PUT DD: Interface for writing view techn. settings to ABAP Dictionary
DDIF_VIEW_ACTIVATE DD: Interface for activating a view
DDIF_VIEW_GET DD: Interface for reading a view from the ABAP Dictionary
DDIF_VIEW_PUT DD: Interface for writing a view in the ABAP Dictionary
