delete

The EGL delete statement removes either a record from a file or a row from a database.

Syntax diagram for the delete statement

record name: Name of the I/O object: an indexed, relative, or SQL record associated with the file record or SQL row being deleted
from resultSetID: ID that ties the delete statement to a get or open statement run earlier in the same program. For details, see resultSetID.

An example is as follows:

  if (userRequest = "D")
    try
      get myRecord forUpdate;
      onException 
        myErrorHandler(12);   // exits the program
    end

    try
      delete myRecord;
      onException 
        myErrorHandler(16);
    end
  end

The behavior of the delete statement depends on the record type. For details on SQL processing, see SQL record.

Indexed or relative record

If you want to delete an indexed or relative record, do as follows:

Issue a get statement for the record and specify the forUpdate option
Issue the delete statement, with no intervening I/O operation against the same file

After you issue the get statement, the effect of the next I/O operation on the same file is as follows:

If the next I/O operation is a replace statement on the same EGL record, the record is changed in the file
If the next I/O operation is a delete statement on the same EGL record, the record in the file is marked for deletion
If the next I/O operation is a get on the same file (with the forUpdate option), a subsequent replace or delete is valid on the newly read file record
If the next I/O operation is a get on the same EGL record (with no forUpdate option) or is a close on the same file, the file record is released without change

For details on the forUpdate option, see get.

SQL record

In the case of SQL processing, use the forUpdate option on an EGL get or open statement to retrieve a row for subsequent deletion:

You can issue a get statement to retrieve the row; or
You can issue an open statement to select a set of rows and then invoke a get next statement to retrieve the row of interest.

In either case, the EGL delete statement is represented in the generated code by an SQL DELETE statement that references the current row in a cursor. You cannot modify that SQL statement, which is formatted as follows:

  DELETE FROM tableName
    WHERE CURRENT OF cursor

If you wish to write your own SQL DELETE statement, use the EGL execute statement.

You cannot use a single EGL delete statement to remove rows from multiple SQL tables.

Related tasks
Syntax diagram