SKIP

SKIP

Move the record pointer to a new position

Syntax

      SKIP [<nRecords>] [ALIAS <idAlias> | <nWorkArea>]

Arguments

<nRecords> is a numeric expression specifying the number of records to move the record pointer from the current position. A positive value moves the record pointer forward and a negative value moves the record pointer backward.

ALIAS <idAlias>|<nWorkArea> specifies the alias name as a literal identifier or the work area as a numeric expression.

SKIP specified with no arguments moves the record pointer forward one record.

Description

SKIP moves the record pointer to a new position relative to the current position in the current work area and within the current filter, if there is one. SKIP is generally used for operations, such as reporting, that need to go to the next record in a database file.

If the alias clause is specified, the pointer can be moved in another work area without SELECTing that work area. SKIP can move either forward or backward. If there is no active index, SKIP moves the record pointer relative to the current position in the target database file. If there is an active index, SKIP moves the pointer relative to the current position in the index instead of the database file.

Attempting to SKIP forward beyond the end of file positions the record pointer at LASTREC() + 1, and EOF() returns true (.T.). Attempting to SKIP backward beyond the beginning of file moves the pointer to the first record, and BOF() returns true (.T.).

In a network environment, any record movement command, including SKIP, makes changes to the current work area visible to other applications if the current file is shared and the changes were made during an RLOCK(). To force an update to become visible without changing the current record position, use SKIP 0. If, however, the changes were made during an FLOCK(), visibility is not guaranteed until the lock is released, a COMMIT is performed, or the file is closed. Refer to the “Network Programming” chapter for more information.

Examples

      .  This example uses SKIP with various arguments and shows their
         results:

      USE Customers NEW
      SKIP
      ? RECNO()                  // Result: 2
      SKIP 10
      ? RECNO()                  // Result: 12
      SKIP -5
      ? RECNO()                  // Result: 7

      .  This example moves the record pointer in a remote work area:

      USE Customers NEW
      USE Invoices NEW
      SKIP ALIAS Customers

      .  This example prints a report using SKIP to move the record
         pointer sequentially through the Customer database file:

      LOCAL nLine := 99
      USE Customers NEW
      SET PRINTER ON
      DO WHILE !EOF()
         IF nLine > 55
            EJECT
            nLine := 1
         ENDIF
            ? Customer, Address, City, State, Zip
            nLine++
            SKIP
         ENDDO
      SET PRINTER OFF
      CLOSE Customers

Seealso

BOF(), COMMIT, DBSKIP(), EOF(), GO, LOCATE, RECNO(), SEEK

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REPLACE

Assign new values to field variables

Syntax

      REPLACE <idField> WITH <exp>
            [, <idField2> WITH <exp2>...]
            [<scope>] [WHILE <lCondition>] [FOR <lCondition>]

Arguments

<idField> is the name of the field variable to be assigned a new value. If <idField> is prefaced with an alias, the assignment takes place in the designated work area.

WITH <exp> defines the value to assign to <idField>.

<scope> is the portion of the current database file to REPLACE. The default is the current record, or NEXT 1. Specifying a condition changes the default to ALL records in the current work area.

WHILE <lCondition> specifies the set of records meeting the condition from the current record until the condition fails.

FOR <lCondition> specifies the conditional set of records to REPLACE within the given scope.

Description

REPLACE is a database command that assigns new values to the contents of one or more field variables in the current record in the specified work areas. The target field variables can be character, date, logical, memo, or numeric. REPLACE performs the same function as the assignment operator (:=) except that it assumes that an unaliased reference is to a field variable. This means that you can assign new values to field variables using assignment statements provided that the field variable references are prefaced with an alias, the FIELD alias, or declared using the FIELD declaration statement.

The default scope of REPLACE is the current record unless a scope or condition is specified. If a scope or condition is specified, the replace operation is performed on each record matching the scope and/or condition.

Warning! When you REPLACE a key field, the index is updated and the relative position of the record pointer within the index is changed. This means that REPLACEing a key field with a scope or a condition may yield an erroneous result. To update a key field, SET ORDER TO 0 before the REPLACE. This ensures that the record pointer moves sequentially in natural order. All open indexes, however, are updated if the key field is REPLACEd.

In a network environment, REPLACEing the current record requires an RLOCK(). REPLACEing with a scope and/or condition requires an FLOCK() or EXCLUSIVE USE of the current database file. If a field is being REPLACEd in another work area by specifying its alias, that record must also be locked with an RLOCK(). Refer to the “Network Programming” chapter for more information.

Examples

      .  This example shows a simple use of REPLACE:

         USE Customer NEW
         APPEND BLANK
         USE Invoices NEW
         APPEND BLANK
         //
         REPLACE Charges WITH Customer->Markup * Cost,;
            Custid WITH Customer->Custid,;
            Customer->TranDate WITH DATE()

      .  This example uses assignment statements in place of the
         REPLACE command:

         FIELD->Charges := Customer->Markup * FIELD->Cost
         FIELD->Custid := Customer->Custid
         Customer->TranDate := DATE()

Seealso

COMMIT, FLOCK(), RLOCK()

C5_COMMIT

 COMMIT
 Perform a solid-disk write for all active work areas
------------------------------------------------------------------------------
 Syntax

     COMMIT

 Description

     COMMIT is a database command that flushes Clipper buffers and
     performs a solid-disk write for all work areas with open database and
     index files.  The solid-disk write capability is available under DOS
     version 3.3 and above.  Under DOS 3.2 or less, COMMIT flushes Clipper
     buffers to DOS.

     In a network environment, issuing a GO TO RECNO() or a SKIP0 will flush
     Clipper's database and index buffers, but only a COMMIT will flush
     the buffers and perform a solid-disk write.  Thus to insure updates are
     visible to other processes, you must issue a COMMIT after all database
     update commands (e.g., APPEND, REPLACE).  To insure data integrity,
     COMMIT should be issued before an UNLOCK operation.  Refer to the
     "Network Programming" chapter in the Programming and Utilities Guide for
     more information on update visibility.

 Notes

     .  COMMIT uses DOS interrupt 21h function 68h to perform the
        solid-disk write.  It is up to the network operating system to
        properly implement this request.  Check with the network vendor to
        see if this is supported.

 Examples

     .  In this example, COMMIT forces a write to disk after a series
        of memory variables are assigned to field variables:

        USE Sales EXCLUSIVE NEW
        MEMVAR->Name := Sales->Name
        MEMVAR->Amount := Sales->Amount
        //
        @ 10, 10 GET MEMVAR->Name
        @ 11, 10 GET MEMVAR->Amount
        READ
        //
        IF UPDATED()
           APPEND BLANK
           REPLACE Sales->Name WITH MEMVAR->Name
           REPLACE Sales->Amount WITH MEMVAR->Amount
           COMMIT
        ENDIF

 Files   Library is CLIPPER.LIB.

See Also: DBCOMMIT() DBCOMMITALL() GO SKIP

 

C5 Commands

 ?|??            Display one or more values to the console
 @...BOX         Draw a box on the screen
 @...CLEAR       Clear a rectangular region of the screen
 @...GET         Create a new Get object and display it
 @...PROMPT      Paint a menu item and define a message
 @...SAY         Display data at a specified screen or printer row and column
 @...TO          Draw a single- or double-line box
 ACCEPT*         Place keyboard input into a memory variable
 APPEND BLANK    Add a new record to the current database file
 APPEND FROM     Import records from a database (.dbf) file or ASCII text file
 AVERAGE         Average numeric expressions in the current work area
 CALL*           Execute a C or Assembler procedure
 CANCEL*         Terminate program processing
 CLEAR ALL*      Close files and release public and private variables
 CLEAR GETS      Release Get objects from the current GetList array
 CLEAR MEMORY    Release all public and private variables
 CLEAR SCREEN    Clear the screen and return the cursor home
 CLEAR TYPEAHEAD Empty the keyboard buffer
 CLOSE           Close a specific set of files
 COMMIT          Perform a solid-disk write for all active work areas
 CONTINUE        Resume a pending LOCATE
 COPY FILE       Copy a file to a new file or to a device
 COPY STRUCTURE  Copy the current .dbf structure to a new database (.dbf) file
 COPY STRU EXTE  Copy field definitions to a .dbf file
 COPY TO         Export records to a database (.dbf) file or ASCII text file
 COUNT           Tally records to a variable
 CREATE          Create an empty structure extended (.dbf) file
 CREATE FROM     Create a new .dbf file from a structure extended file
 DELETE          Mark records for deletion
 DELETE FILE     Remove a file from disk
 DELETE TAG      Delete a tag
 DIR*            Display a listing of files from a specified path
 DISPLAY         Display records to the console
 EJECT           Advance the printhead to top of form
 ERASE           Remove a file from disk
 FIND*           Search an index for a specified key value
 GO              Move the pointer to the specified identity
 INDEX           Create an index file
 INPUT*          Enter the result of an expression into a variable
 JOIN            Create a new database file by merging from two work areas
 KEYBOARD        Stuff a string into the keyboard buffer
 LABEL FORM      Display labels to the console
 LIST            List records to the console
 LOCATE          Search sequentially for a record matching a condition
 MENU TO         Execute a lightbar menu for defined PROMPTs
 NOTE*           Place a single-line comment in a program file
 PACK            Remove deleted records from a database file
 QUIT            Terminate program processing
 READ            Activate full-screen editing mode using Get objects
 RECALL          Restore records marked for deletion
 REINDEX         Rebuild open indexes in the current work area
 RELEASE         Delete public and private memory variables
 RENAME          Change the name of a file
 REPLACE         Assign new values to field variables
 REPORT FORM     Display a report to the console
 RESTORE         Retrieve memory variables from a memory (.mem) file
 RESTORE SCREEN* Display a saved screen
 RUN             Execute a DOS command or program
 SAVE            Save variables to a memory (.mem) file
 SAVE SCREEN*    Save the current screen to a buffer or variable
 SEEK            Search an order for a specified key value
 SELECT          Change the current work area
 SET ALTERNATE   Echo console output to a text file
 SET BELL        Toggle sounding of the bell during full-screen operations
 SET CENTURY     Modify the date format to include or omit century digits
 SET COLOR*      Define screen colors
 SET CONFIRM     Toggle required exit key to terminate GETs
 SET CONSOLE     Toggle console display to the screen
 SET CURSOR      Toggle the screen cursor on or off
 SET DATE        Set the date format for input and display
 SET DECIMALS    Set the number of decimal places to be displayed
 SET DEFAULT     Set the CA-Clipper default drive and directory
 SET DELETED     Toggle filtering of deleted records
 SET DELIMITERS  Toggle or define GET delimiters
 SET DESCENDING  Change the descending flag of the controlling order
 SET DEVICE      Direct @...SAYs to the screen or printer
 SET EPOCH       Control the interpretation of dates with no century digits
 SET ESCAPE      Toggle Esc as a READ exit key
 SET EXACT*      Toggle exact matches for character strings
 SET EXCLUSIVE*  Establish shared or exclusive USE of database files
 SET FILTER      Hide records not meeting a condition
 SET FIXED       Toggle fixing of the number of decimal digits displayed
 SET FORMAT*     Activate a format when READ is executed
 SET FUNCTION    Assign a character string to a function key
 SET INDEX       Open one or more order bags in the current work area
 SET INTENSITY   Toggle enhanced display of GETs and PROMPTs
 SET KEY         Assign a procedure invocation to a key
 SET MARGIN      Set the page offset for all printed output
 SET MEMOBLOCK   Change the block size for memo files
 SET MESSAGE     Set the @...PROMPT message line row
 SET OPTIMIZE    Change the setting that optimizes using open orders
 SET ORDER       Select the controlling order
 SET PATH        Specify the CA-Clipper search path for opening files
 SET PRINTER     Toggle echo of output to printer or set the print destination
 SET PROCEDURE*  Compile procedures and functions into the current object file
 SET RELATION    Relate two work areas by a key value or record number
 SET SCOPE       Change the boundaries for scoping keys in controlling order
 SET SCOPEBOTTOM Change bottom boundary for scoping keys in controlling order
 SET SCOPETOP    Change top boundary for scoping keys in controlling order
 SET SCOREBOARD  Toggle the message display from READ or MEMOEDIT()
 SET SOFTSEEK    Toggle relative seeking
 SET TYPEAHEAD   Set the size of the keyboard buffer
 SET UNIQUE*     Toggle inclusion of non-unique keys into an index
 SET WRAP*       Toggle wrapping of the highlight in menus
 SKIP            Move the record pointer to a new position
 SORT            Copy to a database (.dbf) file in sorted order
 STORE*          Assign a value to one or more variables
 SUM             Sum numeric expressions and assign results to variables
 TEXT*           Display a literal block of text
 TOTAL           Summarize records by key value to a database (.dbf) file
 TYPE            Display the contents of a text file
 UNLOCK          Release file/record locks set by the current user
 UPDATE          Update current database file from another database file
 USE             Open an existing database (.dbf) and its associated files
 WAIT*           Suspend program processing until a key is pressed
 ZAP             Remove all records from the current database file

 

C5 Database Commands

Database Commands and Statements

APPEND BLANK

Add a new record to current database file.

APPEND BLANK

APPEND FROM :

Import records from a (.dbf) or ASCII file

APPEND FROM <xcFile>
     [FIELDS <idField list>]
     [<scope>] 
     [WHILE <lCondition>] 
     [FOR <lCondition>]
     [SDF | DELIMITED [WITH BLANK | <xcDelimiter>] |
     [VIA <xcDriver>]]

AVERAGE :

Average numeric expressions in the current work area

AVERAGE <nExp list> TO <idVar list> 
     [<scope>] 
     [WHILE <lCondition>] 
     [FOR <lCondition>]

CLEAR ALL* :

Close files and release public and private variables.

CLEAR ALL

CLOSE :

Close a specific set of files

CLOSE [<idAlias> | ALL | ALTERNATE | DATABASES | FORMAT |INDEXES ]

COMMIT :

Perform a solid-disk write for all active work areas

COMMIT

CONTINUE :

Resume a pending LOCATE

CONTINUE

COPY STRUCTURE :

Copy the current (.dbf) structure to a new (.dbf) file

COPY STRUCTURE [FIELDS <idField list>] TO <xcDatabase>

COPY STRUCTURE EXTENDED :

Copy field definitions to a (.dbf) file

COPY STRUCTURE EXTENDED TO <xcExtendedDatabase>

COPY TO :

Export records to a new (.dbf) or ASCII file

COPY [FIELDS <idField list>] TO <xcFile>
     [<scope>] 
     [WHILE <lCondition>] 
     [FOR <lCondition>]
     [SDF | DELIMITED [WITH BLANK | <xcDelimiter>] |
     [VIA <xcDriver>]]

COUNT :

Tally records to a variable

COUNT TO <idVar>
     [<scope>] 
     [WHILE <lCondition>] 
     [FOR <lCondition>]

CREATE :

Create an empty structure extended (.dbf) file

CREATE <xcExtendedDatabase>

CREATE FROM :

Create a new (.dbf) file from a structure extended file

CREATE <xcDatabase> 
    FROM <xcExtendedDatabase> 
    [NEW]
    [ALIAS <xcAlias>] 
    [VIA <cDriver>]

DELETE :

Mark records for deletion

DELETE [<scope>] 
    [WHILE <lCondition>]
    [FOR <lCondition>]

FIELD :

Declare database field names

FIELD <idField list> [IN <idAlias>]

FIND* :

Search an index for a specified key value

FIND <xcSearchString>

GO :

Move the record pointer to a specific record

GO[TO] <nRecord> | BOTTOM | TOP

JOIN :

Merge two (.dbf) files to create a new (.dbf) file

JOIN WITH <xcAlias> TO <xcDatabase>
     FOR <lCondition> 
     [FIELDS <idField list>]

LOCATE :

Search sequentially for a record matching a condition

LOCATE [<scope>] 
    FOR <lCondition>
    [WHILE <lCondition>]

PACK :

Remove deleted records from a database file

PACK

RECALL :

Restore records marked for deletion

RECALL [<scope>] 
     [WHILE <lCondition>]
     [FOR <lCondition>]

REPLACE :

Assign new values to field variables

REPLACE <idField> WITH <exp>
    [, <idField2> WITH <exp2>...]
    [<scope>] 
    [WHILE <lCondition>] 
    [FOR <lCondition>]

SEEK :

Search an index for a specified key value

SEEK <expSearch>

SELECT :

Change the current work area

SELECT <xnWorkArea> | <idAlias>

SET DELETED :

Toggle filtering of deleted records

SET DELETED on | OFF | <xlToggle>

SET EXCLUSIVE :

Establish shared or exclusive USE of database files

SET EXCLUSIVE ON | off | <xlToggle>

SET FILTER :

Hide records not meeting a condition

SET FILTER TO [<lCondition>]

SET  MEMOBLOCK :

     Change the block size for memo files

     SET MEMOBLOCK TO <nSize>

SET PATH :

Specify the search path for opening files

SET PATH TO [<xcPathspec list>]

SET RELATION :

Relate two work areas by a key value or record number

SET RELATION TO [<expKey> | <nRecord> INTO <xcAlias>]
    [, [TO] <expKey2> | <nRecord2> INTO <xcAlias2>...]
    [ADDITIVE]

SET SOFTSEEK :

Toggle relative SEEKing

SET SOFTSEEK on | OFF | <xlToggle>

SET UNIQUE :

Toggle the inclusion of nonunique keys into an index

SET UNIQUE on | OFF | <xlToggle>

SKIP :

Move the record pointer to a new position

SKIP [<nRecords>] [ALIAS <idAlias> | <nWorkArea>]

SORT :

Copy to a (.dbf) file in sorted order

SORT TO <xcDatabase> ON <idField> [/[A | D][C]]
    [, <idField2> [/[A | D][C]]...]
    [<scope>] 
    [WHILE <lCondition>] 
    [FOR <lCondition>]

SUM :

Sum numeric expressions to variables

SUM <nExp list> TO <idVar list>
    [<scope>] 
    [WHILE <lCondition>] 
    [FOR <lCondition>]

TOTAL

Summarize records by key value to a (.dbf) file

TOTAL ON <expKey> FIELDS <idField list>
    TO <xcDatabase>
    [<scope>] 
    [WHILE <lCondition>] 
    [FOR <lCondition>]

UNLOCK :

Release file/record locks set by the current user

     UNLOCK [ALL]

UPDATE : 

Update current database file from another database file

UPDATE FROM <xcAlias>
   ON <expKey> [RANDOM]
   REPLACE <idField> WITH <exp>
   [, <idField2> WITH <exp2>...]

USE

Open an existing (.dbf) and its associated files

USE [<xcDatabase>
    [INDEX <xcIndex list>]
    [ALIAS <xcAlias>] 
    [EXCLUSIVE | SHARED]
    [NEW] [READONLY]
    [VIA <cDriver>]]

ZAP

Remove all records from the current database file

ZAP