1  –  AS EACH ROW OF select-expression

    Creates a simple result table.

    After SQL creates the result table from the select expression,
    the DO clause executes a set of SQL statements (compound-use-
    statement) for each result table row. See Select_Expressions
    in the Oracle Rdb SQL Reference Manual for more information on
    select expressions.

2  –  beginning-label:

    Assigns a name to the FOR statement. A named FOR loop is called
    a labeled FOR 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.

3  –  compound-use-statement

    Identifies the SQL statements allowed in a compound statement
    block. See Compound_Stmt for a complete description of a compound
    statement.

4  –  DO compound-use-statement

    Executes a block of SQL statements once for each execution of the
    loop as defined by the starting and ending value expressions.

5  –  END_FOR

    Syntax:

    END FOR | END FOR ending-label

    Marks the end of a FOR 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 the FOR loops of multistatement procedures easier
    to read, especially in very complex procedure blocks.

6  –  FOR variable name

    Specifies a variable to hold a value that is incremented each
    time the FOR loop is executed. The variable is decremented if the
    REVERSE keyword is specified. The starting value for the variable
    is the first value expression. Execution of the FOR loop ends
    when the variable has been incremented (or decremented) to the
    value specified with the second value expression.

    Marks the end of a FOR 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 the FOR loops of multistatement procedures easier
    to read, especially in very complex procedure blocks.

7  –  IN value-expression-option

    Syntax options:

       IN value-expr TO value-expr
       IN REVERSE value-expr TO value-expr

    Specifies how often the compound-use-statement should be
    executed. When the REVERSE keyword is not specified, the variable
    contained in the FOR variable-name is incremented at the end of
    each execution of the FOR loop body. When the REVERSE keyword
    is specified, the variable contained in the FOR variable-name is
    decremented at the end of each execution of the FOR loop body.

    Both value expressions are evaluated once before the loop
    executes. The TO value-expression is evaluated first to ensure
    that references to the FOR loop variable do not cause side
    effects.

8  –  select_expression

    See Select_Expressions in the Oracle Rdb SQL Reference Manual for
    a complete description of select expressions.

9  –  STEP value-expr

    Controls the size of the increment between loop interations. The
    step size is specified using a numeric value expression.

    If omitted the default step size is 1.

    SQL> begin
    cont> declare :i integer;
    cont> for :i in 1 to 20 step 5
    cont> do
    cont>     trace :i;
    cont> end for;
    cont> end;
    ~Xt: 1
    ~Xt: 6
    ~Xt: 11
    ~Xt: 16

                                   NOTE

       Even if the loop control variable is an INTERVAL type the
       STEP must be numeric type. In addition the value must be
       greater than zero - use the REVERSE keyword to decrement the
       loop control variable.

10  –  value-expr

    Syntax:

       IN value-expr TO value-expr
       IN REVERSE value-expr TO value-expr

    Specifies how often the compound-use-statement should be
    executed. When the REVERSE keyword is not specified, the variable
    contained in the FOR variable-name is incremented at the end of
    each execution of the FOR loop body. When the REVERSE keyword
    is specified, the variable contained in the FOR variable-name is
    decremented at the end of each execution of the FOR loop body.

    Both value expressions are evaluated once before the loop
    executes. The TO value-expression is evaluated first to ensure
    that references to the FOR loop variable do not cause side
    effects.