__DBSTRUCTFILTER()
Filter a database structure array
- Syntax
- __dbStructFilter( <aStruct>, [<aFieldList>] ) --> aStructFiltered
- Arguments
- <aStruct> is a multidimensional array with database fields structure, which is usually the output from DBSTRUCT(), where each array element has the following structure:
Position | Description | dbstruct.ch |
|
1 | cFieldName | DBS_NAME |
2 | cFieldType | DBS_TYPE |
3 | nFieldLength | DBS_LEN |
4 | nDecimals | DBS_DEC |
- <aFieldList> is an array where each element is a field name. Names could be specified as uppercase or lowercase.
- Returns
- __dbStructFilter() return a new multidimensional array where each element is in the same structure as the original <aStruct>, but the array is built according to the list of fields in <aFieldList>. If <aFieldList> is empty, __dbStructFilter() return reference to the original <aStruct> array.
- Description
- __dbStructFilter() can be use to create a sub-set of a database structure, based on a given field list.
- Note that field names in MUST be specified in uppercase or else no match would be found.
- SET EXACT has no effect on the return value.
- Examples
- LOCAL aStruct, aList, aRet
- aStruct := { { "CODE", "N", 4, 0 }, ;
- { "NAME", "C", 10, 0 }, ;
- { "PHONE", "C", 13, 0 }, ;
- { "IQ", "N", 3, 0 } }
- aList := { "IQ", "NAME" }
- aRet := __dbStructFilter( aStruct, aList )
- // { { "IQ", "N", 3, 0 }, { "NAME", "C", 10, 0 } }
- aRet := __dbStructFilter( aStruct, {} )
- ? aRet == aStruct // .T.
- aList := { "iq", "NOTEXIST" }
- aRet := __dbStructFilter( aStruct, aList )
- // { { "IQ", "N", 3, 0 } }
- aList := { "NOTEXIST" }
- aRet := __dbStructFilter( aStruct, aList ) // {}
- // Create a new file that contain part of the original structure
- LOCAL aStruct, aList, aRet
- USE TEST
- aStruct := DBSTRUCT()
- aList := { "NAME" }
- DBCREATE( "OnlyName.DBF", __dbStructFilter( aStruct, aList ) )
- Status
Ready
- Compliance
- __dbStructFilter() is a Harbour extension. CA-Clipper has an internal undocumented function named __FLEDIT() that does exactly the same thing. The new name gives a better description of what this function does.
- Platforms
- All
- Files
- Header file is dbstruct.ch Library is rdd
- See Also