DFSORT OMIT Substring Search
A substring search allows us to filter records by looking for specific substrings within a larger character field. DFSORT treats a substring as a portion of a field within a record that we can isolate based on its starting position and length. Substring searches are performed using the OMIT statements, focusing on a specific portion of a field.
Syntax -
//SYSIN DD *
SORT FIELDS=COPY
OMIT COND=(field1_starting_position, field1_length, SS,
relational_operator, substring_constant)
/*| field1_starting_position | Specifies the starting position of field1 to be compared |
| field1_length | Specifies the length of the field1 to be compared |
| SS | Specifies the search and filtering should be done based on the substring_constant. |
| relational_operator | used for condition comparison. The available operators are -
EQ Equal to NE Not equal to GT Greater than GE Greater than or equal to LT Less than LE Less than or equal to |
| substring_constant | Specifies the substring used to filter. |
Examples -
Scenario1 - Basic Substring Search.
OMIT COND=(10,2,CH,SS,C'HI')This statement includes records where the 2-character field starting at position 10 not equals 'HI'. It looks at only the 2 bytes starting at position 10 in the record, rather than comparing the entire field.
Scenario2 - Using Multiple Substring Conditions with AND
OMIT COND=(5,3,CH,SS,C'XYZ',AND,20,4,CH,SS,C'ABCD')This includes records where - the substring starting at position 5 (3 bytes long) is not equal to 'XYZ', and the substring starting at position 20 (4 bytes long) is not equal to 'ABCD'. Both conditions must be true for a record to be included.
Scenario3 - Substring Search with OR
OMIT COND=(1,2,CH,SS,C'AA',OR,10,3,CH,SS,C'999')This example includes records where - the substring starting at position 1 (2 bytes) is not equal to 'AA', or the substring starting at position 10 (3 bytes) is not equal to '999'. If either condition is true, the record is included.