Delphi FDMemTable内存表操作

本文整理自网络，侵删。

 

unit Umemtable;

interface

uses
System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs, System.Rtti,
FMX.Layouts, FMX.Grid, FireDAC.Stan.Intf, FireDAC.Stan.Option, FireDAC.Stan.Param,
FireDAC.Stan.Error, FireDAC.DatS, FireDAC.Phys.Intf, FireDAC.DApt.Intf, Data.DB,
FireDAC.Comp.DataSet, FireDAC.Comp.Client, FMX.Controls.Presentation, FMX.StdCtrls,
Data.Bind.EngExt, Fmx.Bind.DBEngExt, Fmx.Bind.Grid, System.Bindings.Outputs,
Fmx.Bind.Editors, Data.Bind.Components, Data.Bind.Grid, Data.Bind.DBScope, FMX.Edit;

type
TForm1 = class(TForm)
Button1: TButton;
FDMemTable1: TFDMemTable;
DataSource1: TDataSource;
Grid1: TGrid;
bndsrcdb1: TBindSourceDB;
bndngslst1: TBindingsList;
lnkgrdtdtsrcBindSourceDB: TLinkGridToDataSource;
Button2: TButton;
Button3: TButton;
Button4: TButton;
Edit1: TEdit;
Edit2: TEdit;
Edit3: TEdit;
lbl1: TLabel;
Label1: TLabel;
Label2: TLabel;
Button5: TButton;
Button6: TButton;
Button7: TButton;
Button8: TButton;
Button9: TButton;
Button10: TButton;
Button11: TButton;
Button12: TButton;
Button13: TButton;
Button14: TButton;
Button15: TButton;
Button16: TButton;
Button17: TButton;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button5Click(Sender: TObject);
procedure Button6Click(Sender: TObject);
procedure Button8Click(Sender: TObject);
procedure Button7Click(Sender: TObject);
procedure Button9Click(Sender: TObject);
procedure Button10Click(Sender: TObject);
procedure Button11Click(Sender: TObject);
procedure Button12Click(Sender: TObject);
procedure Button13Click(Sender: TObject);
procedure Button14Click(Sender: TObject);
procedure Button15Click(Sender: TObject);
procedure Button16Click(Sender: TObject);
procedure Button17Click(Sender: TObject);
private

{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;
Id: Integer;

implementation

{$R *.fmx}

procedure TForm1.Button10Click(Sender: TObject);
begin
//清空
FDMemTable1.EmptyView;
end;

procedure TForm1.Button11Click(Sender: TObject);
var
FRow, FRow2: TFDDatSRow;
begin
FRow := FDMemTable1.Table.Rows.Add([1, 'Hello', '2015-09-15']);
FRow2 := FDMemTable1.Table.NewRow();
FRow2.SetValues([2, 'Hello2', '2015-09-15']);
FDMemTable1.Table.Rows.Add(FRow2);
//以下方法2条记示增加成功
FDMemTable1.CachedUpdates;
FDMemTable1.CommitUpdates;
// FDMemTable1.ApplyUpdates;
// FDMemTable1.CommitUpdates;
end;

procedure TForm1.Button12Click(Sender: TObject);
begin
FDMemTable1.Filter := 'Value = ' + QuotedStr('Hello');
FDMemTable1.Filtered := True;
end;

procedure TForm1.Button13Click(Sender: TObject);
begin
//FDMemTable1.Filter := 'Value = ''Hello''';
FDMemTable1.Filter := 'Value = ''Hel*''';
//foCaseInsensitive时，“Filter”属性中的条件字符串文字与字段值进行比较时，不区分大小写。
//foNoPartialCompare强制Delphi将星号（*）解释为原义字符而非通配符。默认情况下，
//FilterOptions设置为空集
FDMemTable1.FilterOptions := [foCaseInsensitive];
FDMemTable1.Filtered := True;

end;

procedure TForm1.Button14Click(Sender: TObject);
begin
FDMemTable1.Filter := 'Value Like ''Hel%''';
FDMemTable1.Filtered := True;

end;

procedure TForm1.Button15Click(Sender: TObject);
begin
FDMemTable1.Filter := 'Id<10 and Value Like ''He%''';
FDMemTable1.Filtered := True;

end;

procedure TForm1.Button16Click(Sender: TObject);
var
FConnIntf: IFDPhysConnection;
FCommIntf: IFDPhysCommand;
oMechFilter: TFDDatSMechFilter;
FDataView: TFDDatSView;
begin

FDataView := FDMemTable1.Table.DefaultView;
FDataView.Sort := 'Id ASC';
//FDataView.Mechanisms.AddSort('Id DESC;Value ASC');
//FDMemTable1.View.Mechanisms.AddSort('Id');
FDataView.Mechanisms.Clear;


// FDMemTable1.View.Sort:=' Id DESC;'
//FDMemTable1.View.SortingMechanism;
// 4) filtering
// oMechFilter := TFDDatSMechFilter.Create('id > 3');
// FDMemTable1.View.Mechanisms.Add(oMechFilter);

// FDefaultView.Mechanisms.Clear;
// // 5) too
// FDMemTable1.View.Mechanisms.AddFilter('Id DESC');
// FDefaultView.Mechanisms.Clear;
// FDefaultView.Mechanisms.Clear;
// // 5) too
// FDefaultView.Mechanisms.AddFilter('id > 5');
// FDefaultView.Mechanisms.Clear;

end;

procedure TForm1.Button17Click(Sender: TObject);
var
oMech: TFDDatSMechFilter;
i: Integer;
FDataView: TFDDatSView;
begin
FDataView := FDMemTable1.Table.DefaultView;
// Locate row using locating mechanism
oMech := TFDDatSMechFilter.Create('Id=5');
oMech.Locator := True;
FDataView.Mechanisms.Add(oMech);
FDataView.Locate(i, True, True);
if i <> -1 then
begin
ShowMessage('找到 删除');
//FDataView.de;
end
else
begin
ShowMessage('NO');
end;
FDataView.Mechanisms.Clear;
end;


procedure TForm1.Button1Click(Sender: TObject);
var
i: Integer;
begin
if FDMemTable1.Active then
FDMemTable1.Close;
with FDMemTable1.FieldDefs do
begin
Clear;
Add('Id', ftInteger, 0, False);
Add('Value', FtString, 20, False);
Add('Time', ftDateTime, 0, False);
end;
with FDMemTable1.IndexDefs do
begin
Clear;
// Add('Index1', 'Id', []); //定义索引 正序
Add('Index1', 'Id', [ixDescending]); //定义索引 倒序
end;
FDMemTable1.CreateDataSet;
for i := 1 to 15 do
begin
FDMemTable1.AppendRecord([i, 'ID' + IntTOSTR(i), Now()]);
end;

end;

procedure TForm1.Button2Click(Sender: TObject);
begin
FDMemTable1.AppendRecord([StrToInt(Edit1.Text), Edit2.Text, StrToDate(Edit3.Text)]);
end;

procedure TForm1.Button5Click(Sender: TObject);
var
fld_Id: TIntegerField;
fld_Value: TStringField;
fld_Time: TDateTimeField;
i: Integer;
begin
//插入
with FDMemTable1 do
begin
DisableControls; //切断数据感知控件
try
Open; //打开
//定义Field
fld_Id := TIntegerField(FieldByName('Id'));
fld_Value := TStringField(FieldByName('Value'));
fld_Time := TDateTimeField(FieldByName('Time'));
for i := 0 to 9 do
begin
Inc(Id);
Append; //附加数据
//赋值
fld_Id.AsInteger := Id;
fld_Value.AsString := 'Hello PFeng!' + inttostr(Id);
fld_Time.AsDateTime := Now;
Post; //确定
end;
//UpdateIndexes;//更新索引
finally
EnableControls; //连接数据感知控件
end;
end;
end;

procedure TForm1.Button6Click(Sender: TObject);
var
fld_Id: TIntegerField;
fld_Value: TStringField;
fld_Time: TDateTimeField;
begin
//更新
with FDMemTable1 do
begin
Open;
fld_Id := TIntegerField(FieldByName('Id'));
fld_Value := TStringField(FieldByName('Value'));
fld_Time := TDateTimeField(FieldByName('Time'));
if Locate('Id', 5, []) then
begin
Edit;
fld_Value.AsString := '内容被修改';
fld_Time.AsDateTime := Now;
Post;
end;
end;
end;

procedure TForm1.Button7Click(Sender: TObject);
var
fld_Id: TIntegerField;
fld_Value: TStringField;
fld_Time: TDateTimeField;
begin
//删除
with FDMemTable1 do
begin
Open;
fld_Id := TIntegerField(FieldByName('Id'));
fld_Value := TStringField(FieldByName('Value'));
fld_Time := TDateTimeField(FieldByName('Time'));
if Locate('Id', 5, []) then
begin
Delete;
//UpdateIndexes;
end;
end;
end;

procedure TForm1.Button8Click(Sender: TObject);
var
fld_Id: TIntegerField;
fld_Value: TStringField;
fld_Time: TDateTimeField;
begin
//查询
with FDMemTable1 do
begin
Open;
fld_Id := TIntegerField(FieldByName('Id'));
fld_Value := TStringField(FieldByName('Value'));
fld_Time := TDateTimeField(FieldByName('Time'));
if Locate('Id', 5, []) then
ShowMessage(fld_Value.AsString);
//还可以用FindKey实现，结合索引速度更快
// kbmMemTable1.IndexFieldNames:='Id';
// if kbmMemtable1.FindKey([5]) then ...
end;
end;

procedure TForm1.Button9Click(Sender: TObject);
var
fld_Id: TIntegerField;
fld_Value: TStringField;
fld_Time: TDateTimeField;
id: Integer;
begin
//循环比较最小值
with FDMemTable1 do
begin
Open;
fld_Id := TIntegerField(FieldByName('Id'));
fld_Value := TStringField(FieldByName('Value'));
fld_Time := TDateTimeField(FieldByName('Time'));
DisableControls;
try
First;
id := fld_Id.AsInteger;
while not Eof do
begin
if id > fld_Id.AsInteger then
id := fld_Id.AsInteger;
Next;
end;
Locate('Id', id, []);
finally
EnableControls;
end;
end;
end;

end.

来源:https://www.cnblogs.com/hnxxcxg/p/5366443.html
 

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