SET DELETED

SET DELETED

Toggle filtering of deleted records

Syntax

      SET DELETED on | OFF | <xlToggle>

Arguments

ON ignores deleted records.

OFF processes deleted records.

<xlToggle> is a logical expression that must be enclosed in parentheses. A value of true (.T.) is the same as ON, and a value of false (.F.) is the same as OFF.

Description

SET DELETED toggles automatic filtering of records marked for deletion in all work areas. When SET DELETED is ON, most commands ignore deleted records. If, however, you refer to a record by record number (GOTO or any command that supports the RECORD scope), the record is not ignored even if marked for deletion. Additionally, SET DELETED ON has no affect on INDEX or REINDEXing.

RECALL ALL honors SET DELETED and does not recall any records.

Notes

. Filtering deleted records in a single work area: To confine the filtering of deleted records to a particular work area, SELECT the work area, and then SET FILTER TO DELETED().

Examples

      .  This example illustrates the effect of using SET DELETED:

      USE Sales NEW
      ? LASTREC()                  // Result: 84
      //
      DELETE RECORD 4
      COUNT TO nCount
      ? nCount                     // Result: 84
      //
      SET DELETED ON
      COUNT TO nCount
      ? nCount                     // Result: 83

Seealso

DELETE, DELETED(), RECALL, SET FILTER

LOCATE

LOCATE

Search sequentially for a record matching a condition

Syntax

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

Arguments

<scope> is the portion of the current database file in which to perform the LOCATE. The default scope is ALL records.

FOR <lCondition> specifies the next record to LOCATE within the given scope.

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

Description

LOCATE is a database command that searches for the first record in the current work area that matches the specified conditions and scope. When you first execute a LOCATE, it searches from the beginning record of the scope for the first matching record in the current work area. It terminates when a match is found or the end of the LOCATE scope is reached. If it is successful, the matching record becomes the current record and FOUND() returns true (.T.). If it is unsuccessful, FOUND() returns false (.F.) and the positioning of the record pointer depends on the controlling scope of the LOCATE.

Each work area can have its own LOCATE condition. The condition remains active until you execute another LOCATE command in that work area or the application terminates.

LOCATE works with CONTINUE. Once a LOCATE has been issued, you can resume the search from the current record pointer position with CONTINUE. There are, however, some exceptions. See note below.

Notes

. CONTINUE: Both the <scope> and the WHILE condition apply only to the initial LOCATE and are not operational for any subsequent CONTINUE commands. To continue a pending LOCATE with a scope or WHILE condition, use SKIP then LOCATE REST WHILE <lCondition> instead of CONTINUE.

Examples

      .  These examples show typical LOCATEs:
      USE Sales INDEX Salesman
      LOCATE FOR Branch = "200"
      ? FOUND(), EOF(), RECNO()         // Result: .T. .F. 5
      LOCATE FOR Branch = "5000"
      ? FOUND(), EOF(), RECNO()         // Result: .F. .T. 85
      .  This example shows a LOCATE with a WHILE condition that is
         continued by using LOCATE REST:
      SEEK "Bill"
      LOCATE FOR Branch = "200" WHILE Salesman = "Bill"
      DO WHILE FOUND()
         ? Branch, Salesman
         SKIP
         LOCATE REST FOR Branch = "200" WHILE ;
                  Salesman = "Bill"
      ENDDO

Seealso

CONTINUE, EOF(), FOUND(), SEEK, SET FILTER

GO

GO

Move the pointer to the specified identity

Syntax

      GO[TO] <xIdentity> | BOTTOM | TOP

Arguments

<xIdentity> is a unique value guaranteed by the structure of the data file to reference a specific item in a data source (database). In a .dbf, identity is the record number. In other data formats, identity is the unique primary key value.

BOTTOM specifies the last logical record in the current work area.

TOP specifies the first logical record in the current work area.

Description

GO[TO] is a database command that positions the record pointer in the current work area at the specified identity. In an Xbase data structure, this identity is the record number because every record, even an empty record, has a record number. In data structures of different design, identity may be defined as something other than record number.

Examples

      .  This example saves the current record number, searches for a
         key, and then restores the record pointer to the saved position:
      FUNCTION KeyExists( xKeyExpr )
         LOCAL nSavRecord := RECNO()      // Save the current record
                                          // pointer position
         LOCAL lFound
         SEEK xKeyExpr
         IF ( lFound := FOUND() )
            .
            .  < statements >
            .
         ENDIF
         GOTO nSavRecord      // Restore the record pointer position
         RETURN ( lFound )

Seealso

DBGOTO(), LASTREC(), RECNO(), SET DELETED, SET FILTER

C5_SET FILTER

SET FILTER
 Hide records not meeting a condition
------------------------------------------------------------------------------
 Syntax

     SET FILTER TO [<lCondition>]

 Arguments

     TO <lCondition> is a logical expression that defines a specific set
     of current work area records accessible for processing.

     SET FILTER TO without an argument deactivates the filter condition.

 Description

     When a FILTER condition is SET, the current work area acts as if it
     contains only the records that match the specified condition.  A filter
     condition is one of the properties of a work area.  Once a FILTER has
     been SET, the condition can be returned as a character string using the
     DBFILTER() function.

     Most commands and functions that move the record pointer honor the
     current filter with the exception of those commands that access records
     by record number.  This includes GOTO, commands specified with the
     RECORD clause, and RELATIONs linked by numeric expression to a work area
     with no active index.

     Once a FILTER is SET, it is not activated until the record pointer is
     moved from its current position.  You can use GO TOP to activate it.

     As with SET DELETED, a filter has no effect on INDEX and REINDEX.

     Note:  Although SET FILTER makes the current work area appear as if
     it contains a subset of records, it, in fact, sequentially processes all
     records in the work area.  Because of this, the time required to process
     a filtered work area will be the same as an unfiltered work area.

 Examples

     .  This example filters Employee.dbf to only those records where
        the age is greater than 50:

        USE Employee INDEX Name NEW
        SET FILTER TO Age > 50
        LIST Lastname, Firstname, Age, Phone
        SET FILTER TO

 Files   Library is CLIPPER.LIB.

See Also: DBFILTER() DBSETFILTER() SET DELETED



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