FIREDAC FDConnection 連接池 連接串

一、FDConnection 連接池

http://docs.embarcadero.com/products/rad_studio/firedac/frames.html?frmname=topic&frmfile=Defining_Connection.html

 

http://docwiki.embarcadero.com/RADStudio/XE8/en/Defining_Connection_%28FireDAC%29

 http://docwiki.embarcadero.com/RADStudio/Berlin/en/Multithreading_(FireDAC)

 

FDManager()->ConnectionDefs->ConnectionDefByName("")

FDManager.ConnectionDefs.ConnectionDefByName(cbDB.Text).Params.Pooled := True

oConn.ConnectionDefName;

 

FDConnection1->Params->Pooled;

$(FDHOME)\FDConnectionDefs.ini

D:\Users\Public\Documents\Embarcadero\Studio\FireDAC\FDConnectionDefs.ini

 

D:\Users\Public\Documents\Embarcadero\Studio\16.0\Samples\Object Pascal\Database\FireDAC\Samples\Comp Layer\TFDConnection\Pooling

從這個官方例子看出使用連接池比不使用連接池的效率提高4倍。

 http://www.cnblogs.com/zhenfei/p/4105515.html

1）FDConnectionDefs.ini文件

[MSSQL_Demo]
DriverID=MSSQL
Server=127.0.0.1
Database=Northwind
User_Name=sa
Password=
MetaDefSchema=dbo
MetaDefCatalog=Northwind
ExtendedMetadata=True

以上代碼存為FDConnectionDefs.ini文件放到當前exe目錄下，程序會自己找到。小節名稱與ConnectionDefByName參數一致。

this->FDManager1->ConnectionDefFileName = "FDConnectionDefs.ini";
this->FDManager1->ConnectionDefs->ConnectionDefByName("MSSQL_Demo")->Params->Pooled = true;

考慮到安全性，密碼需要加密，所以建議用方法2或3。

2）代碼動態創建IFDStanConnectionDef

uses
  FireDAC.Comp.Client, FireDAC.Stan.Intf; var oDef: IFDStanConnectionDef; begin oDef := FDManager.ConnectionDefs.AddConnectionDef; oDef.Name := 'MSSQL_Connection'; oDef.DriverID := 'MSSQL'; oDef.Server := '127.0.0.1'; oDef.Database := 'Northwind'; oDef.OSAuthent := True; oDef.MarkPersistent; oDef.Apply; ..................... FDConnection1.ConnectionDefName := 'MSSQL_Connection'; FDConnection1.Connected := True;

3）連接參數

var
  oParams: TStrings; begin oParams := TStringList.Create; oParams.Add('Server=127.0.0.1'); oParams.Add('Database=Northwind'); oParams.Add('OSAuthent=Yes'); FDManager.AddConnectionDef('MSSQL_Connection', 'MSSQL', oParams); ..................... FDConnection1.ConnectionDefName := 'MSSQL_Connection'; FDConnection1.Connected := True;

 c++  FDManager()->AddConnectionDef("", "", para);
其他

FDManager.ConnectionDefFileName := ExtractFilePath(Application.ExeName) + 'myconndef.ini'; FDManager.ConnectionDefFileAutoLoad := True; oConn := TFDConnection.Create(nil); oConn.ConnectionDefName := 'myconn'; oConn.Connected := True;

 

Create Connection def

void __fastcall TForm35::Button5Click(TObject *Sender)
{
    TStrings *para;
    para = new TStringList();
    para->Add("Server=192.168.1.1");
    para->Add("Database=db");
    para->Add("User_Name=sa");
    para->Add("Password=123");

    FDManager()->AddConnectionDef("sqlPTT", "MSSQL", para);

    FDConnection1->ConnectionDefName = "sqlPTT";
    Label1->Caption = this->FDConnection1->ResultConnectionDef->BuildString();
    delete para;

    int startTime = GetTickCount();
    for (int i = 0; i < 10; i++)
    {
        this->Button1->Click();
    }
    Caption = (GetTickCount() - startTime) / 1000.0;
}

 

use pool 

void __fastcall TForm35::Button1Click(TObject *Sender)
{
    TFDConnection *con;
    con = new TFDConnection(NULL);
    con->ConnectionDefName = FDConnection1->ConnectionDefName;

    TFDQuery *qry;
    qry = new TFDQuery(NULL);
    qry->Connection = con;
    qry->SQL->Text = "select count(*) from tt";
    qry->Open();
    con->Close();

    delete con;
    delete qry;

}

連接池比普通連接塊4倍！

 

連接字符串ConnectString

mssql帶端口號

Server={127.0.0.1,9433};User_Name=sa;;Password=123;Database=dbname;DriverID=MSSQL

Name=Unnamed;Database=mydb;User_Name=sa;Password=123;Server=127.0.0.1;DriverID=MSSQL

FDConnection1.ConnectionString := 'DriverID=MSSQL;Server=127.0.0.1;Database=Northwind;User_name=sa;Password=123;';
Database=car;User_Name=sa;Password=;Server=127.0.0.1,9433;DriverID=MSSQL

mysql
Database=testdata;User_Name=root;Password=root;Server=127.0.0.1;DriverID=MySQL;CharacterSet=utf8

sqlite:
Database=D:\msdb.db;DriverID=SQLite

執行十條sql語句性能比較。
1、一個連接打開，不關閉，耗時0.184ms
2、使用連接池，耗時0.265ms
3、不使用連接池，0.71ms
 oracle連接字符串ip地址輸入10.0.0.2:1521/orcl


  FDConnection1.Params.DriverID:='SQLite';
  FDConnection1.Params.Database := 'Demo.db';

以前ADO連接
ADOConstr = PromptDataSource(0, ADOConnection1->ConnectionString);

DBF連接串
Provider = Microsoft.Jet.OLEDB.4.0 ;Data Source ={0};Extended Properties=dBASE IV

SQLite連接字符串
Name=Unnamed;Database=E:\Bin\posdata.sqlite;DriverID=SQLite
MYSQL連接串
Name=Unnamed;Database=tData;User_Name=root;Password=root;Server=127.0.0.1;DriverID=MySQL;CharacterSet=utf8;Port=3306

ADO連接字符串

Provider=SQLOLEDB.1;Password=123;Persist Security Info=True;User ID=sa;Initial Catalog=mydb;Data Source=127.0.0.1

 
--ORACLE
DriverID=Ora
Database=(DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521)) )  (CONNECT_DATA = (SERVICE_NAME = orcl)))
User_Name=DI_EHR
Password=neusoft
AuthMode=Normal
CharacterSet=UTF8

DB2
http://docwiki.embarcadero.com/RADStudio/Rio/en/Connect_to_IBM_DB2_Server_(FireDAC)

Use Cases

• Connect to DB2 using the existing database alias:

DriverID=DB2
Alias=addemo
User_Name=db2admin
Password=mypwd
MetaDefSchema=db2admin

• Connect to DB using full connection information:

DriverID=DB2
Server=127.0.0.1
Database=addemo
Port=50000
Protocol=TCPIP
User_Name=db2admin
Password=mypwd
MetaDefSchema=db2admin