TClientDataSet.Filter Property

Specifies the text of the current filter.

Pascal

property Filter: string;

C++

__property AnsiString Filter;

Description

Use Filter to specify a dataset filter. When filtering is applied to a client dataset, only those records that meet a filter's conditions are available to an application. Filter contains the string that describes the filter condition. Client datasets support the following set of filter operations: See the Limiting what records appear link at the bottom of this topic for a complete list of available filter operations.

Operator or function ComparisonsExampleComment

Operator or function Comparisons	Example	Comment
=	State = 'CA'
<>	State <> 'CA'
>=	DateEntered >= '1/1/1998'
<=	Total <= 100,000
>	Percentile > 50
<	Field1 < Field2
BLANK	State <> 'CA' or State = BLANK	Blank records do not appear unless explicitly included in the filter.
IS NULL	Field1 IS NULL
IS NOT NULL	Field1 IS NOT NULL
Logical operators
and	State = 'CA' and Country = 'US'
or	State = 'CA' or State = 'MA'
not	not (State = 'CA')
Arithmetic operators
+	Total + 5 > 100	Applies to numbers, strings, or date (time) + number
-	Field1 - 7 <> 10	Applies to numbers, dates, or date (time) - number
*	Discount * 100 > 20	Applies to numbers only
/	Discount > Total / 5	Applies to numbers only
String functions
Upper	Upper(Field1) = 'ALWAYS'
Lower	Lower(Field1 + Field2) = 'josp'
Substring	Substring(DateString,8) = '1998' \| Substring(DateString,1,3) = 'JAN'	Value goes from position of second argument to end or number of chars in third arg. First char has position 1.
Trim	Trim(Field1 + Field2) \| Trim(Field1, '-')	removes third argument from front and back. If no third argument, trims spaces.
TrimLeft	TrimLeft(StringField) \| TrimLeft(Field1, '$') <> ''	See Trim
TrimRight	TrimRight(StringField) \| TrimRight(Field1, '.') <> ''	See Trim
DateTime functions
Year	Year(DateField) = 2000
Month	Month(DateField) <> 12
Day	Day(DateField) = 1
Hour	Hour(DateField) < 16
Minute	Minute(DateField) = 0
Second	Second(DateField) = 30
GetDate	GetDate - DateField > 7	Represents current date and time
Date	DateField = Date(GetDate)	Returns the date portion of a datetime value
Time	TimeField > Time(GetDate)	Returns the time portion of a datetime value
Miscellaneous
Like	Memo LIKE '%filters%'	Works like SQL-92 without the ESC clause. When applied to BLOB fields, FilterOptions determines whether case is considered.
In	Day(DateField) in (1,7)	Works like SQL-92. Second argument is a list of values all with the same type.
*	State = 'M*'	Wildcard for partial comparisons