Release 10.1A: OpenEdge Development:
Progress 4GL Reference

REPEAT statement

Begins a block of statements that are processed repeatedly until the block ends in one of several ways.

Block properties

Iteration, record scoping, frame scoping, transactions by default.

Syntax

[ label : ] REPEAT [ FOR record [ , record ] ... ] [ preselect-phrase ] [ query-tuning-phrase ] [ variable = expression1 TO expression2 [ BY k ] ] [ WHILE expression ] [ TRANSACTION ] [ on-endkey-phrase ] [ on-error-phrase ] [ on-quit-phrase ] [ on-stop-phrase ] [ frame-phrase ]

FOR record [ , record ] . . .

Names a record buffer and scopes the buffer to the block. The scope of a record determines when the buffer is cleared and the record is written back to the database. See OpenEdge Development: Progress 4GL Handbook for more information on record scoping and blocks.

To access a record in a table defined for multiple databases, you must qualify the record’s table name with the database name. See the Record phrase reference entry for more information.

preselect-phrase

Goes through a table to select the records that meet the criteria you specify in a record-phrase. PRESELECT creates a temporary index that contains pointers to each of the preselected records in the database table. You can then use other statements, such as FIND NEXT, to process those records. Following is the syntax for preselect-phrase:

PRESELECT [ EACH | FIRST | LAST ] record-phrase [ , { EACH | FIRST | LAST } record-phrase ] ... [ [ BREAK ] { BY expression [ DESCENDING ] } ... ]

For more information, see the PRESELECT phrase reference entry.

query-tuning-phrase

Allows programmatic control over the execution of a DataServer query. Following is the syntax for the query-tuning-phrase:

QUERY-TUNING ( [ BIND-WHERE | NO-BIND-WHERE ] [ CACHE-SIZE integer ] [ DEBUG { SQL | EXTENDED } | NO-DEBUG ] [ INDEX-HINT | NO-INDEX-HINT ] [ JOIN-BY-SQLDB | NO-JOIN-BY-SQLDB ] [ LOOKAHEAD | NO-LOOKAHEAD ] [ SEPARATE-CONNECTION | NO-SEPARATE-CONNECTION ] )

For more information, see the OpenEdge DataServer Guides, OpenEdge Data Management: DataServer for Microsoft SQL Server , OpenEdge Data Management: DataServer for ODBC , and OpenEdge Data Management: DataServer for ORACLE .

variable = expression1 TO expression2 [ BY k ]

Indicates the name of a field or variable whose value you are incrementing in a loop. The expression1 is the starting value for variable on the first iteration of the loop. The k is the amount to add to variable after each iteration and must be a constant. When variable exceeds expression2 (or is less than expression2 if k is negative), the loop ends. Because expression1 is compared to expression2 at the start of the first iteration of the block, the block can be executed zero times. The expression2 is reevaluated with each iteration of the block.

WHILE expression

Indicates the condition during which the REPEAT block processes the statements within it. The block iterates as long as the condition specified by the expression is TRUE. The expression is any combination of constants, field names, and variable names that yield a logical value.

TRANSACTION

Identifies the REPEAT block as a system transaction block. Progress starts a system transaction for each iteration of a transaction block if there is no active system transaction. See OpenEdge Development: Progress 4GL Handbook for more information on transactions.

on-endkey-phrase

Describes the processing that takes place when the ENDKEY condition occurs during a block. Following is the syntax for the ON ENDKEY phrase:

ON ENDKEY UNDO [ label1 ] [ , LEAVE [ label2 ] | , NEXT [ label2 ] | , RETRY [ label1 ] | , RETURN [ ERROR | NO-APPLY ] [ return-string ] ]

For more information, see the ON ENDKEY phrase reference entry.

on-error-phrase

Describes the processing that takes place when there is an error during a block. This is the syntax for the ON ERROR phrase:

ON ERROR UNDO [ label1 ] [ , LEAVE [ label2 ] | , NEXT [ label2 ] | , RETRY [ label1 ] | , RETURN [ ERROR | NO-APPLY ] [ return-string ] ]

For more information, see the ON ERROR phrase reference entry.

on-quit-phrase

Describes the processing that takes place when a QUIT statement is executed during a block. This is the syntax for the ON QUIT phrase:

ON QUIT [ UNDO [ label1 ] ] [ , LEAVE [ label2 ] | , NEXT [ label2 ] | , RETRY [ label1 ] | , RETURN [ ERROR | NO-APPLY ] [ return-string ] ]

For more information, see the ON QUIT phrase reference entry.

on-stop-phrase

Describes the processing that takes place when the STOP conditions occurs during a block. This is the syntax for the ON STOP phrase:

ON STOP UNDO [ label1 ] [ , LEAVE [ label2 ] | , NEXT [ label2 ] | , RETRY [ label1 ] | , RETURN [ ERROR | NO-APPLY ] [ return-string ] ]

For more information, see the ON STOP phrase reference entry.

frame-phrase

Specifies the overall layout and processing properties of a frame. For more information, see the Frame phrase reference entry.

Example

In this menu procedure, if you press END-ERROR or ENDKEY when the procedure prompts you for your menu selection, any data you have entered as a selection is undone and the procedure continues to prompt you for a menu selection:

r-rpt.p

DEFINE VAR Selection AS INTEGER FORMAT "9". FORM skip(3) "0 - Exit" at 32 "1 - Edit Customer File" at 32 "2 - List Customer File" at 32 "3 - Edit Item File" at 32 "4 - List Item File" at 32 "Enter Choice" TO 30 Selection AUTO-RETURN HEADER "Application Name" "Master Menu" AT 34 "Company" TO 79 WITH NO-BOX NO-LABELS CENTERED FRAME menu. /* Create the procedures that are called from the following block. */ REPEAT ON ENDKEY UNDO, RETRY: UPDATE Selection WITH FRAME menu. HIDE FRAME menu. CASE(Selection): WHEN 0 THEN LEAVE. WHEN 1 THEN RUN custedit.p. WHEN 2 THEN RUN custrpt.p. WHEN 3 THEN RUN itemedit.p. WHEN 4 THEN RUN itemrpt.p. OTHERWISE DO: BELL. MESSAGE "Not a valid choice. Try again.". END. END CASE. END. /* REPEAT */

Notes

Within a REPEAT block, if you are using the FIND NEXT or FIND PREV statement and you change the value of an index field, Progress makes that change in the index table at the end of the UPDATE or SET statement. Therefore, if you change the value so that the record appears later in the index table, you will see the record again if you FIND NEXT. If you change the value so that the record appears earlier in the index table, you see the record again if you FIND PREV.

REPEAT: FIND NEXT customer. UPDATE cust-num. END.

In this example, if you change customer 1 to customer 300, you see that customer record again at the end of the procedure.

When you use the PRESELECT option, Progress builds a special index table that is not updated when index values change. For example, add the PRESELECT option to the above example:

REPEAT PRESELECT EACH customer: FIND NEXT customer. UPDATE cust-num. END.

In this example, if you change customer 2 to customer 200, you do not see that customer record until you look it up with a new procedure.

SpeedScript – The invalid options are: on-endkey-phrase and on-quit-phrase.

See also

DO statement, END statement, Frame phrase, ON ENDKEY phrase, ON ERROR phrase, ON QUIT phrase, ON STOP phrase