Navigational DML Programming Techniques › Checking for Set Membership

Checking for Set Membership

When accessing the database, you may find it necessary to obtain information about an owner or member record's set-membership status. To obtain set-specific information for a record occurrence, use the IF statement. By using the IF statement, you can determine:

• If the current occurrence of a specified set contains any member record occurrences (Is it empty?)
• If the current record of run unit participates as a member in a specified set defined with either the optional or the manual set membership option (Is it currently connected to an occurrence of the specified set?)

Each IF statement contains a conditional phrase and an imperative statement that specifies further action based on the outcome of the evaluation.

'Native VSAM users'. The IF statement is not allowed for sets defined with member records that are stored in native VSAM data sets.

Use of the IF EMPTY statement and the IF MEMBER statement are discussed below.