首页 / 软件开发 / Delphi / Delphi FireDAC 下的 Sqlite（五） 数据的插入、更新和删除

Delphi FireDAC 下的 Sqlite（五） 数据的插入、更新和删除2015-02-13先在空白窗体上添加: TFDConnection、TFDPhysSQLiteDriverLink、TFDGUIxWaitCursor、TFDQuery、TDataSource、TDBGrid（并在设计时关联好）.你也可以复制下面文本框中的内容, 然后直接往窗体上贴, 以快速完成以上的添加过程: object DBGrid1: TDBGrid Left = 16 Top = 88 Width = 361 Height = 329 DataSource = DataSource1 TabOrder = 0 TitleFont.Charset = DEFAULT_CHARSET TitleFont.Color = clWindowText TitleFont.Height = -11 TitleFont.Name = "Tahoma" TitleFont.Style = [] end object FDConnection1: TFDConnection Left = 34 Top = 24 end object FDPhysSQLiteDriverLink1: TFDPhysSQLiteDriverLink Left = 143 Top = 24 end object FDGUIxWaitCursor1: TFDGUIxWaitCursor Provider = "Forms" Left = 260 Top = 24 end object FDQuery1: TFDQuery Connection = FDConnection1 Left = 344 Top = 24 end object DataSource1: TDataSource DataSet = FDQuery1 Left = 420 Top = 24 end object Button1: TButton Left = 400 Top = 88 Width = 75 Height = 25 Caption = "Button1" TabOrder = 1 OnClick = Button1Click end object Button2: TButton Left = 400 Top = 136 Width = 75 Height = 25 Caption = "Button2" TabOrder = 2 OnClick = Button2Click end object Button3: TButton Left = 400 Top = 192 Width = 75 Height = 25 Caption = "Button3" TabOrder = 3 OnClick = Button3Click end object Button4: TButton Left = 400 Top = 240 Width = 75 Height = 25 Caption = "Button4" TabOrder = 4 OnClick = Button4Click end end

代码:

{建立}procedure TForm1.FormCreate（Sender: TObject）;constdbPath = "C:TempSQLiteTest.sdb";strTable = "CREATE TABLE MyTable（Id integer PRIMARY KEY AUTOINCREMENT, Name string（10）, Age byte）"; //Id, Name, Age 三个字段//integer PRIMARY KEY AUTOINCREMENT: 自增字段beginif FileExists（dbPath） then DeleteFile（dbPath）;FDConnection1.ConnectionString := "DriverID=SQLite; Database=" + dbPath;FDConnection1.ExecSQL（strTable）;FDQuery1.Open（"SELECT * FROM MyTable"）;end;{插入}procedure TForm1.Button1Click（Sender: TObject）;conststrInsert = "INSERT INTO MyTable（Name, Age） VALUES（:name, :age）"; //:name, :age 的方式（后面还要以数组的方式给出相应的值）, 这比字符串的 Format 函数还要方便.beginFDConnection1.ExecSQL（strInsert, ["AAA", 11]）;FDConnection1.ExecSQL（strInsert, ["BBB", 22]）;FDConnection1.ExecSQL（strInsert, ["CCC", 33]）;FDConnection1.ExecSQL（strInsert, ["DDD", 44]）;FDConnection1.ExecSQL（strInsert, ["EEE", 55]）;FDQuery1.Refresh;end;{更新}procedure TForm1.Button2Click（Sender: TObject）;beginFDConnection1.ExecSQL（"UPDATE MyTable SET Age=:a WHERE Name=:n", [Random（100）, "AAA"]）;FDQuery1.Refresh;end;{删除}procedure TForm1.Button3Click（Sender: TObject）;beginFDConnection1.ExecSQL（"DELETE FROM MyTable WHERE Age>33"）;FDQuery1.Refresh;end;{查询符合条件的第一个结果}procedure TForm1.Button4Click（Sender: TObject）;varV: Variant;beginV := FDConnection1.ExecSQLScalar（"SELECT Age FROM MyTable WHERE Name = :x", ["BBB"]）;ShowMessage（V）;end;