General query component design (continued)
Author: nxyc_twz@163.com
Some time ago, due to work, innocent documents, please understand! I will organize all relevant documents and source code for this component.
Set the default match type
Procedure tdbfilterdialog.setDefaultMatchType (const value: tdbfiltermatchty);
Begin
// Set the default match type
FDEFAULTMATCHPE: = Value;
IF assigned (fdialog) and not (csdesigning in componentstate) THEN
Case fdefaultmatchtype of
FDMATHNONE:
Begin
FDIALOG.GRPSEARCHPE.ITEMINDEX: = 0;
FDIALOG.CBXNONMATCHING.CHECKED: = TRUE;
END;
FDMATCHRANGE:
FDIALOG.PGECRITERIA.ACTIVEPAGE: = fdialog.tabbyrange;
Else
FDIALOG.GRPSEARCHPE.ITEMINDEX: = Integer (fdefaultmatchType);
END;
END;
Set field
Procedure TDBFILTERDIALOG.SETFIELDS;
VAR
I, J, P: Integer;
Field, Display: String;
Begin
// Set field
FDIALOG.LSTALLFIELDS.CLEAR; / / Clear all fields
IF ffields.count = 0 THEN
Begin
For i: = 0 to fdataset.fieldlist.count - 1 do
If fdatanet.fields [i] .visible life // Define Query Fields
FDIALOG.LSTALLFIELDS.ITEMS.ADDObject (fdataSet.fields [i] .displayName, fdatanet.fieldlist.fields [i]);
end
Else
For j: = 0 to ffields.count - 1 do
Begin
P: = POS (';', ffields.strings [j]);
Field: = COPY (Ffields.Strings [J], 1, P - 1);
IF P = Length (ffields.strings [j]) THEN
Display: = Field
Else
Display: = COPY (Ffields.Strings [J], P 1, Length (ffields.strings [j]));
For i: = 0 to fdataset.fieldlist.count - 1 do
if fdatanet.fieldlist.fields [i] .fieldname = field the
FDIALOG.LSTALLFIELDS.ITEMS.AddObject (Display, fdataSet.fieldList.fields [i]);
END;
IF fdialog.lstallfields.Items.count> 0 THEN
Begin
FDIALOG.LSTALLFIELDS.ITEMINDEX: = 0;
Fdialog.fieldsListBoxClick (nil); / / Click the list box
END;
END;
Set field list
Procedure TDBFILTERDIALOG.SETFIELDSLISL (Const Value: Tstringlist); Begin
/ / Set field list
Ffields.Assign (Value);
END;
Set SQL
Procedure TdbfilterDialog.setoriginalsql (Const Value: Tstrings);
VAR
i: integer;
Begin
/ / Set SQL statement
IF fortersql.text <> value.text dam
Begin
Foriginalsql.clear;
ForiginalSql.Addstrings (value);
IF not (cslineing in componentstate) THEN
Ffields.clear;
FDIALOG.NEWSQL; // New SQL query
END;
For i: = 0 to foriGinalvariables.count - 1 do
TDBVARIABLE (foriginalvariables [i]). Free; // Defines the parameter data variable class
ForiginalVariables.clear;
IF TSTRINGS (getordprop (fdataaset, sqlprop)). Text = '' Then
EXIT;
For i: = 0 to TQuery (fdataset) .Params.count - 1 DO
ForiginalVariables.Add (TDBVARIABLE.CREATE (TQuery (fdataaset) .Params [i] .name, tQuery (fdataset) .Params [i] .value)); / / Define Parameter Data Variable Class
SetFields; // Set field
END;
Restore SQL
Procedure tdbfilterdialog.restoresql;
VAR
i: integer;
Begin
/ / Restore SQL statement
// disable the controls while we are working
FDataSet.disableControls;
FDataSet.Close;
// clear the existing sql and variable declarations
// restore the Original SQL and Variables
SetordProp (FDataSet, Sqlprop, Integer (forterSQL);
If fdatanet is tdatathten
For i: = 0 to foriGinalvariables.count - 1 do
TQuery (fdataaset) .Parambyname (tdbvariable (foriginalvariables [i]). Variablename) .Value: =
TDBVARIABLE (ForiginalVariables [i]). VariableValue
Else
For i: = 0 to foriGinalvariables.count - 1 do
TQuery (fdataaset) .Parambyname (tdbvariable (foriginalvariables [i]). Variablename) .Value: =
TDBVARIABLE (foriginalvariables [i]). VariableValue;
FDataSet.Open;
Setfields;
FDataSet.enableControls;
Fmodifiedsql.assign (Tstrings (getordprings (fdataset, sqlprop));
END;
Save the parameter value
Procedure tdbfilterdialog.saveparamvalues; var
i: integer;
Begin
/ / Save the parameter value
If fdatanet is tdatathten
For i: = 0 to foriGinalvariables.count - 1 do
TDBVARIABLE (foriginalvariables [i]). VariableValue: =
TQuery (fdataset) .Parambyname (tdbvariable (foriginalvariables [i]). Variablename) .value
Else
For i: = 0 to foriGinalvariables.count - 1 do
TDBVARIABLE (foriginalvariables [i]). VariableValue: =
TQuery (fdataset) .Parambyname (tdbvariable (foriginalvariables [i]). Variablename) .value;
END;
Load filter dialog
Procedure tdbfilterdialog.loaded;
VAR
i: integer;
Begin
inherited;
IF assigned (fdataset) and not (csdesigningin company) THEN
Begin
Setfields;
Originalsql.assign (Tstrings (getordprings));
For i: = 0 to TQuery (fdataset) .Params.count - 1 DO
ForiginalVariables.Add (TDBVARIABLE.CREATE (TQuery (fdataset) .Params [i] .name,
TQuery (fdataset) .Params [i] .value);
END;
END;
Transmit message
Procedure tdbfilterdialog.Notification (Acomponent: Tcomponent;
Operation: TOPERATION);
Begin
inherited;
IF (ACOMPONENT = fdatanet) and (Operation = Opremove) THEN
FDataSet: = NIL;
END;
Constructor
Constructor TDBFilterDialog.create (Aowner: Tcomponent);
Begin
//Constructor
Inherited Create (Aowner);
FDIALOG: = TMYDBFILTERDIALOG.CREATE (Self);
FOPTIONS: = [fdshowcasensensitive, fdshownonmatching];
FDEFAULTMATCHPE: = fdmatchstart;
Caption: = SDBFILTERCAPTION;
Ffields: = tstringlist.create;
Foriginalsql: = TSTRINGLIST.CREATE;
FMODIFIEDSQL: = TSTRINGLIST.CREATE;
ForiginalVariables: = TLIST.CREATE;
END;
Destructor
Destructor TdbfilterDialog.destroy;
VAR
i: integer;
Begin
FDIALOG.FREE;
Ffields.free;
Foriginalsql.Free;
Fmodifiedsql.free;
For i: = 0 to foriGinalVariables.count - 1 DotdbVariable (foriginalvariables [i]).
ForiginalVariables.Free;
Inherited destroy;
END;
Execute query
Function TDBFILTERDIALOG.EXECUTE: BOOLEAN;
VAR
Currentsql: tstrings;
Begin
// Execute data query
Currentsql: = Tstrings (getordprings (fdataaset, sqlprop);
/ / Check if the SQL statement has changed
IF not fmodifiedsql.equals (currentsql) THEN
Originalsql: = Currentsql;
IF fdialog.lstallfields.Items.count = 0 THEN
Setfields;
FDIALOG.GRPSEARCHPE.ITEMINDEX: = Integer (fdefaultmatchType);
IF fdshowcasensensitive in options the
FDIALOG.CBXCaseSensitive.visible: = TRUE
Else
FDIALOG.CBXCaseSensitive.visible: = false;
IF fdshownonmatch in options
FDIALOG.CBXNONMATCHING.Visible: = TRUE
Else
FDIALOG.CBXNONMATCHING.Visible: = FALSE
IF fdcasensitive in options the
FDIALOG.CBXCaseSensitive.Checked: = TRUE
Else
FDIALOG.CBXCaseSensitive.Checked: = false;
SaveParamvalues; // Save the parameter value
Result: = fdialog.showmodal = mrok; // Click the OK button
IF results
Rebuildsql; // Rebuild SQL statement
END;
