SAP ABAP Programming for all ENTRIES in use Guide concatenate a table with an inner table

In ABAP development, for a clustered table that cannot use joins or for an inner table that needs to use Select, we generally use the for all entries in statement to concatenate the table with the inner table . query out the required data, such as

TYPES :  BEGIN of T_asnum,
Asnum like Asmd-asnum,
END of T_asnum.
DATA :gt_asnum TYPE TABLE of T_asnum.

CLEAR: G_matkl,Gt_asnum.
SELECT SingleMatkl fromZmm_ys_jsdlx intoG_matklWHEREJsdlx= G_jsdlx1.
SELECTAsnum fromAsmd intoTABLEGt_asnumWHEREMatkl= G_matkl.

SELECT *
fromZmm_ys_yw
intoTABLEGt_order
for AllENTRIESinchGt_asnum
WHEREAsnum= Gt_asnum-Asnum.

so the query condition is The value of the Asnum field exists in the Asnum field value of the inner table Gt_asnum

SAP ABAP Programming for all ENTRIES in use Guide concatenate a table with an inner table