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

RECALL

Restore records marked for deletion

Syntax

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

Arguments

<scope> is the portion of the current database file to RECALL. The default scope is the current record, or NEXT 1. If a condition is specified, the default scope becomes ALL.

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 RECALL within the given scope.

Description

RECALL is a database command that restores records marked for deletion in the current work area. This is the inverse of the DELETE command. If DELETED is ON, RECALL can restore the current record or a specific record, if you specify a RECORD scope. Note that once you PACK a database file, all marked records have been physically removed from the file and cannot be recovered.

In a network environment, RECALLing the current record requires an RLOCK(). RECALLing several records requires an FLOCK() or EXCLUSIVE USE of the current database file. Refer to the “Network Programming” chapter for more information.

Examples

      .  This examples show the results of RECALL:

      USE Sales NEW
      //
      DELETE RECORD 4
      ? DELETED()               // Result: .T.
      //
      RECALL
      ? DELETED()               // Result: .F.

Seealso

DELETE, DELETED, FLOCK(), PACK, RLOCK(), SET DELETED

DELETE

DELETE

Mark records for deletion

Syntax

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

Arguments

<scope> is the portion of the current database file to DELETE. If a scope is not specified, DELETE acts only on the current record. If a conditional clause is specified, the default becomes ALL records.

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 DELETE within the given scope.

Description

DELETE is a database command that tags records so they can be filtered with SET DELETED ON, queried with DELETED(), or physically removed from the database file with PACK. In addition, display commands such as LIST and DISPLAY identify deleted records with an asterisk (*) character. Once records are deleted, you can reinstate them by using RECALL. If you want to remove all records from a database file, use ZAP instead of DELETE ALL and PACK.

Any deleted record can be recalled as long as the PACK or ZAP command has not been issued. Once the PACK or ZAP command has been issued, the deleted data cannot be retrieved.

In a network environment, DELETE requires the current record be locked with RLOCK() if you are deleting a single record. If you are deleting several records, the current database file must be locked with FLOCK() or USEed EXCLUSIVEly. Refer to the “Network Programming” chapter in the Programming and Utilities Guide for more information.

Notes

. DELETE with SET DELETED ON: If the current record is deleted with SET DELETED ON, it will be visible until the record pointer is moved.

Examples

      .  This example demonstrates use of the FOR clause to mark a set
         of records for deletion:
      USE Sales INDEX Salesman NEW
      DELETE ALL FOR Inactive

Seealso

DBEVAL(), DELETED(), FLOCK(), PACK, RECALL, RLOCK()

Harbour All Functions – D

Date()
Day()
Days()

DaysInMonth()
DaysToMonth()

dbAppend()
dbClearFilter()
dbCloseAll()
dbCloseArea()
dbCommit()
dbCommitAll()
dbCreate()
dbDelete()
dbEval()
dbF()
dbFilter()
dbGoBottom()
dbGoTo()
dbGoTop()
dbReCall()
dbRLock()
dbRLockList()
dbRUnlock()
dbSeek()
dbSelectArea()
dbSetDriver()
dbSetFilter()
dbSkip()
dbSkipper()
dbStruct()
dbUnlock()
dbUnlockAll()
dbUseArea()

DecToBin()
DecToHexa()
DecToOctal()

Deleted()
Descend()
DevOutPict()
DirChange()
DirRemove()
DiskSpace()

DMY()
Do()
DoW()

DOY
DToC()

DToR
DToS()

Harbour Database Functions

Database Functions

AFields Fills referenced arrays with database field information
Alias Returns the alias name of a work area
BOF Test for the beggining-of-file condition
dbAppend Appends a new record to a database file
dbClearFilter Clears the current filter condiction in a work area
dbCloseAll Close all open files in all work areas.
dbCloseArea Close a database file in a work area
dbCommit Updates all index and database buffers for a given workarea
dbCommitAll Flushes the memory buffer and performs a hard-disk write
dbCreate Creates an empty database from a array
dbDelete Mark a record for deletion in a database
dbEval Performs a code block operation on the current Database
DBF Alias name of a work area
dbFilter Return the filter expression in a work area
dbGoBottom Moves the record pointer to the bottom of the database
dbGoto Position the record pointer to a specific location
dbGoTop Moves the record pointer to the top of the database
dbRecall Recalls a record previousy marked for deletion
dbSeek Searches for a value based on an active index
dbSelectArea Change to another work area
dbSetDriver Establishes the RDD name for the selected work area
dbSetFilter Establishes a filter condition for a work area
dbSkip Moves the record pointer in the selected work area
dbSkipper Helper function to skip a database
dbStruct Builds a multidimensional array of a database structure
dbUseArea Opens a work area and uses a database file
Deleted Tests the record’s deletion flag
EOF Test for end-of-file condition
FCount Counts the number of fields in an active database
FieldDeci Determines the number of decimal places of a given numeric field
FieldGet Obtains the value of a specified field
FieldName Return the name of a field at a numeric field location
FieldPos Return the ordinal position of a field
FieldPut Set the value of a field variable
FieldSize Determines the size of a given field
FieldType Determines the type of a given field
Found Determine the success of a previous search operation
Header Return the length of a database file header
LastRec Returns the number of records in an active work area or database
LUpdate Yields the date the database was last updated
RecCount Counts the number of records in a database
RecNo Returns the current record number or identity
RecSize Returns the size of a single record in an active database
Select Returns the work area number for a specified alias
Used Checks whether a database is in use in a work area

PACK

PACK

Remove records marked for deletion from a database

Syntax

      PACK

Arguments

(This command has no arguments)

Description

This command removes records that were marked for deletion from the currently selected database. This command does not pack the contents of a memo field; those files must be packed via low-level fuctions.

All open index files will be automatically reindexed once PACK command has completed its operation. On completion, the record pointer is placed on the first record in the database.

Examples

      USE tests NEW INDEX tests
      DBGOTO( 10 )
      DELETE NEXT 10
      PACK
      USE

Compliance

Clipper

Seealso

DBEVAL(), DELETE, DELETED(), ZAP, RECALL

C5_DELETED

 DELETED()
 Return the deleted status of the current record
------------------------------------------------------------------------------
 Syntax

     DELETED() --> lDeleted

 Returns

     DELETED() returns true (.T.) if the current record is marked for
     deletion; otherwise, it returns false (.F.).  If there is no database
     file in USE in the current work area, DELETED() returns false (.F.).

 Description

     DELETED() is a database function that determines if the current record
     in the active work area is marked for deletion.  Since each work area
     with an open database file can have a current record, each work area has
     its own DELETED() value.

     By default, DELETED() operates on the currently selected work area.  It
     will operate on an unselected work area if you specify it as part of an
     aliased expression (see example below).

     In applications, DELETED() is generally used to query the deleted status
     as a part of record processing conditions, or to display the deleted
     status as a part of screens and reports.

 Examples

     .  This example uses DELETED() in the current and in an
        unselected work area:

        USE Customer NEW
        USE Sales NEW
        ? DELETED()                     // Result: .F.
        DELETE
        ? DELETED()                     // Result: .T.
        ? Customer->(DELETED())         // Result: .F.

     .  This example uses DELETED() to display a record's deleted
        status in screens and reports:

        @ 1, 65 SAY IF(DELETED(), "Inactive", "Active")

 Files   Library is CLIPPER.LIB.

See Also: DELETE PACK RECALL SET DELETED



C5 Database Functions

AFIELDS() :

Fill arrays with the structure of the current database file

AFIELDS([<aFieldNames>],
    [<aTypes>],
    [<aWidths>],
    [<aDecimals>]) --> nFields

ALIAS() : 

Return a specified work area alias

ALIAS([<nWorkArea>]) --> cAlias

BOF() : 

Determine when beginning of file is encountered

BOF() --> lBoundary

DBAPPEND() : 

Add a new record

DBAPPEND() --> NIL

DBCLEARFILTER() : 

Clear a filter condition

    DBCLEARFILTER() –> NIL

DBCLEARIND() :  Close all indexes for the current work area

    DBCLEARINDEX() --> NIL

DBCLEARREL() : 

Clear active relations

DBCLEARRELATION() --> NIL

DBCLOSEALL() : 

Close all occupied workareas

DBCLOSEALL() --> NIL

DBCLOSEAREA() : 

Close a workarea

DBCLOSEAREA() --> NIL

DBCOMMIT() : 

Flush pending updates

DBCOMMIT() --> NIL

DBCOMMITALL() : 

Flush pending updates in all workareas

DBCOMMITALL() --> NIL

DBCREATE() : 

Create a database file from a database structure array

DBCREATE(<cDatabase>, <aStruct> [, <cDriver> ] ) --> NIL

DBCREATEIND() : 

Create an Index

   DBCREATEINDEX(<cIndexName>, <cKeyExpr>,
        [<bKeyExpr>], [<lUnique>]) --> NIL

DBDELETE() : 

Mark a record for deletion

DBDELETE() --> NIL

DBEDIT() : 

        Browse records in a table layout

    DBEDIT([<nTop>], [<nLeft>],
        [<nBottom>], <nRight>],
        [<acColumns>],
        [<cUserFunction>],
        [<acColumnSayPictures> | <cColumnSayPicture>],
        [<acColumnHeaders> | <cColumnHeader>],
        [<acHeadingSeparators> | <cHeadingSeparator>],
        [<acColumnSeparators> | <cColumnSeparator>],
        [<acFootingSeparators> | <cFootingSeparator>],
        [<acColumnFootings> | <cColumnFooting>]) --> NIL

DBEVAL() : 

Evaluate a code block for each record

DBEVAL(<bBlock>,
    [<bForCondition>],
    [<bWhileCondition>],
    [<nNextRecords>],
    [<nRecord>],
    [<lRest>]) --> NIL

DBF()* : 

Return current alias name

DBF() --> cAlias

DBFIELDINFO() : 

Return and optionally change information about a field

   DBFIELDINFO(<nInfoType>,

        <nFieldPos>,
        [<expNewSetting>]) --> uCurrentSetting

DBFILEGET() : 

Insert the contents of a field into a file

     DBFILEGET(<nFieldPos>, <cTargetFile>, <nMode>)
        --> lSuccess

DBFILEPUT() : 

Insert the contents of a file into a field

     DBFILEPUT(<nFieldPos>, <cSourceFile>)
        --> lSuccess

 DBFILTER() : 

Return the current filter expression as a character string

DBFILTER() --> cFilter

DBGOBOTTOM() : 

Move to the last logical record

DBGOBOTTOM() --> NIL

DBGOTO() : 

Move to a particular record

DBGOTO(<nRecordNumber>) --> NIL

DBGOTOP() : 

Move to the first logical record

DBGOTOP() --> NIL

DBINFO() : 

         Return and optionally change database file information

    DBINFO(<nInfoType>, [<expNewSetting>])
        --> uCurrentSetting

DBORDERINFO() :          Return and optionally change information about orders and index files

    DBORDERINFO(<nInfoType>,   [<cIndexFile>],
        [<cOrder> | <nPosition>],
        [<expNewSetting>]) --> uCurrentSetting

DBRECALL() : 

Reinstate a record marked for deletion

DBRECALL() --> NIL

DBRECORDINFO() :

         Return and optionally change information about a record

    DBRECORDINFO(<nInfoType>,
        [<nRecord>],
        [<expNewSetting>]) --> uCurrentSetting

DBREINDEX() :

         Recreate all active indexes for the current work area

    DBREINDEX() --> NIL

DBRELATION() :

Return the linking expression of a specified relation

DBRELATION( <nRelation> ) --> cLinkExp

DBRLOCK() :      

         Lock the record at the current or specified identity

    DBRLOCK([<xIdentity>]) --> lSuccess

DBRLOCKLIST()          Return an array of the current lock list

   DBRLOCKLIST() --> aRecordLocks

DBRSELECT() :

Return the target workarea number of a relation

DBRSELECT( <nRelation> ) --> nWorkArea

DBRUNLOCK()    

          Release all or specified record locks

    DBRUNLOCK([<xIdentity>]) --> NIL

DBSEEK() : 

Search for a key value

DBSEEK(<expKey>, [<lSoftSeek>]) --> lFound

DBSELECTAR() : 

Change the current workarea

DBSELECTAREA(<nArea> | <cAlias>) --> NIL

DBSETDRIVER() : 

Set the default database driver

DBSETDRIVER([<cDriver>]) --> cCurrentDriver

DBSETFILTER() : 

Set a filter condition

DBSETFILTER(<bCondition>, [<cCondition>]) --> NIL

DBSETINDEX()    

         Empty orders from an order bag into the order list

    DBSETINDEX(<cOrderBagName>) --> NIL

DBSETORDER()

Set the controlling order

    DBSETORDER(<nOrderNum>) --> NIL

DBSETRELAT() :

Relate two workareas

DBSETRELATION( <nArea> | <cAlias>, <bExpr>, [<cExpr>]) --> NIL

DBSKIP() : 

Move relative to the current record

DBSKIP([<nRecords>]) --> NIL

DBSTRUCT() : 

Create an array containing the structure of a database file

DBSTRUCT() --> aStruct

DBUNLOCK()

Release all locks for the current work area

    DBUNLOCK() --> NIL

DBUNLOCKALL()

Release all locks for all work areas

    DBUNLOCKALL() --> NIL

DBUSEAREA() : 

Use a database file in a workarea

DBUSEAREA( [<lNewArea>],
    [<cDriver>],
    <cName>,
    [<xcAlias>],
    [<lShared>],
    [<lReadonly>]) --> NIL

DELETED() : 

Return the deleted status of the current record

DELETED() --> lDeleted

EOF() : 

Determine when end of file is encountered

EOF() --> lBoundary

FCOUNT() : 

Return the number of fields in the current (.dbf) file

FCOUNT() --> nFields

FIELD() : 

Return a field name from the current (.dbf) file

    FIELD/FIELD(<nPosition>) --> cFieldName

FIELDBLOCK() :

Return a set-get code block for a field variable

FIELDBLOCK(<cFieldName>) --> bFieldBlock

FIELDGET() : 

Retrieve the value of a field using the ordinal position of the field in the database structure

FIELDGET(<nField>) --> ValueField

FIELDNAME() : 

Return a field name from the current (.dbf) file

FIELDNAME/FIELD(<nPosition>) --> cFieldName

FIELDPOS() : 

Return the position of a field in a workarea

FIELDPOS(<cFieldName>) --> nFieldPos

FIELDPUT() : 

Set the value of a field variable using the ordinal position of the field in the database structure

FIELDPUT(<nField>, <expAssign>) --> ValueAssigned

FIELDWBLOCK() : 

Return a set-get block for a field in a given workarea

FIELDWBLOCK(<cFieldName>, <nWorkArea>) --> bFieldWBlock

FLOCK() : 

Lock an open and shared database file

    FLOCK() –> lSuccess

FOUND() : 

Determine if the previous search operation succeeded

FOUND() --> lSuccess

HEADER() : 

Return the current database file header length

HEADER() --> nBytes

LASTREC() : 

Determine the number of records in the current (.dbf) file

LASTREC() | RECCOUNT()* --> nRecords

LUPDATE() : 

Return the last modification date of a (.dbf) file

LUPDATE() --> dModification

RECCOUNT()* : 

Determine the number of records in the current (.dbf) file

RECCOUNT()* | LASTREC() --> nRecords

RECNO() : 

Return the current record number of a work area

RECNO() --> nRecord

RECSIZE() : 

Determine the record length of a database (.dbf) file

RECSIZE() --> nBytes

RLOCK()

Lock the current record in the active work area

    RLOCK() --> lSuccess

SELECT() : 

Determine the work area number of a specified alias

SELECT([<cAlias>]) --> nWorkArea

USED() : 

Determine if a database file is in USE

USED() --> lDbfOpen