1  –  beginning-label

    Assigns a name to a control loop. A beginning label used with the
    LEAVE statement lets you perform a controlled exit from a loop. A
    named loop is called a labeled loop statement. If you include an
    ending label, it must be identical to its corresponding beginning
    label. A beginning label must be unique within the procedure in
    which the label is contained.

2  –  compound-use-statement

    Identifies the SQL statements allowed in a compound statement
    block. See the Compound_Statement HELP topic for the list of
    valid statements.

3  –  END_LOOP

    Marks the end of a control loop. If you choose to include the
    optional ending label, it must match exactly its corresponding
    beginning label. An ending label must be unique within the
    procedure in which the label is contained.

    The optional end-label argument makes multistatement procedures
    easier to read, especially in very complex multistatement
    procedure blocks.

4  –  LOOP

    Marks the start of a control loop. A LOOP statement enables you
    to execute the associated sequence of SQL statements called a
    compound statement. After SQL executes the statements within the
    loop, control returns to the LOOP statement at the top of the
    loop for subsequent statement execution. Looping occurs until
    SQL encounters an error exception or executes a LEAVE statement.
    In either case, SQL passes control out of the LOOP block to the
    statement immediately after the LOOP statement.