Generally we check data in ECC from srm like creating a function module in ECC and calling from srm system using destination statement.Using META_READ_TABLE we can avoid this.
META_READ_TABLE function module is used to check data in ECC from SRM in srm system itself.
lt_options - where clause to function module
lt_fields - Fields names for which the data needs(long tables)
lt_contents - contains data in a single string.
we can get logical system from function module "BBP_GET_BACKEND_SYSTEMS"
A) Small Tables :
Table T024W is small table so no need to specify lt_fields.
But we need to specify where condition ,Here I am check whether the plant having purchase organisation or not so passing werks field to lt_options
Passing plant from front-end srm portal.
lt_contents contain data of T024W table.
B)Large Tables : When comes to large table we need to specify required fields if not we will encounter with performance issues.
Here I am checking material extended to plant or not
As Marc table is very large so we need to specify only required fields.
So here iam passing matnr,werks & ekgrp fields
Passing plant & material as where condition from front-end srm portal
CONCATENATE 'AND ' 'MATNR' = ' `'` lc_matnr `'` into lwa_options-text respecting Blanks
APPEND lwa_options TO lt_options[].
we will get data of matnr,werks,ekgrp into lt_contents as a string.