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()
| 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 |
DBSELECTAREA()
Change the current work area
------------------------------------------------------------------------------
Syntax
DBSELECTAREA(<nArea> | <cAlias>) --> NIL
Arguments
<nArea> is a numeric value between zero and 250, inclusive, that
specifies the work area being selected.
<cAlias> is a character value that specifies the alias of a
currently occupied work area being selected.
Returns
DBSELECTAREA() always returns NIL.
Description
DBSELECTAREA() causes the specified work area to become the current work
area. All subsequent database operations will apply to this work area
unless another work area is explicitly specified for an operation.
DBSELECTAREA() performs the same function as the standard SELECT
command. For more information, refer to the SELECT command.
Notes
. Selecting zero: Selecting work area zero causes the lowest
numbered unoccupied work area to become the current work area.
. Aliased expressions: The alias operator (->) can temporarily
select a work area while an expression is evaluated and automatically
restore the previously selected work area afterward. For more
information, refer to the alias operator (->).
Examples
. The following example selects a work area via the alias name:
cLast := "Winston"
DBUSEAREA( .T., "DBFNTX", "Sales", "Sales", .T. )
DBSETINDEX( "SALEFNAM" )
DBSETINDEX( "SALELNAM" )
//
DBUSEAREA( .T., "DBFNTX", "Colls", "Colls", .T. )
DBSETINDEX( "COLLFNAM" )
DBSETINDEX( "COLLLNAM" )
//
DBSELECTAREA( "Sales" ) // select "Sales" work area
//
IF ( Sales->(DBSEEK(cLast)) )
IF Sales->( DELETED() ) .AND. Sales->( RLOCK() )
Sales->( DBRECALL() )
? "Deleted record has been recalled."
ENDIF
ELSE
? "Not found"
ENDIF
Files Library is CLIPPER.LIB.
See Also: DBUSEAREA() RLOCK() UNLOCK SELECT SELECT() RLOCK()
