Connection strings in Web.Config to connect different databases.

1) SQL Server

appSettings
add key="SqlConnectionString" value="Server=ServerName;
DataBase=DataBaseName;User Id=sa;Password = sa"
/appSettings

Or

appSettings
add key="SqlConnectionString"
value="Server=(local);Database=DBName2;UID=sa;PWD= "
/appSettings

Or

appSettings add key ="SqlConnectionString" value="Provider=SQLOLEDB; Data Source=server_name_or_address; Initial Catalog=database_name; User ID=username; Password=password"
/appSettings

User System.Data.SqlClient namespace to open the connection

2) MS Access

appSettings
add key = "MsAccessConnectionString"
Value = "Provider=Microsoft.Jet.OLEDB.4.0;
Data Source=c:\DB\Volume.mdb;"
/appSettings

User System.Data.Oledb namespace to open the connection

3) Oracle

appSettings
add key="OracleConnectionString"
Value="Provider=OraOLEDB.Oracle.1;
Password=mypass;
Persist Security Info=True;
User ID=me;
Data Source=DatabaseName;"
/appSettings

User System.Data.Oledb namespace to open the connection

4) LDAP

appSettings
add key="LDAPConnectString"
value="LDAP://Domain.com/DC=Domain,
DC=com"
/appSettings


5) DB2

appSettings
add key="connMainDB1" value="data source=ipaddy;
initial catalog=db1;persist security info=False;
user id=blah;password=blah;workstation id=webserver;
packet size=4096"
/appSettings

4) Microsoft Access

Provider=MSDASQL; Driver={Microsoft Access Driver (*.mdb)}; DBQ=C:\path\filename.mdb;

5) Microsoft Excel

Provider=MSDASQL; Driver={Microsoft Excel Driver (*.xls)}; DBQ=C:\path\filename.xls;

6) Microsoft Text

Provider=MSDASQL; Driver={Microsoft Text Driver (*.txt; *.csv)}; DBQ=C:\path\;

DSN Connection

Provider=MSDASQL; DSN=data_source_name; UID=username; PWD=password;

DataTable already belongs to another DataSet & DataRow already belongs to another DataRow.

Error: DataTable already belongs to another DataSet

Try in this way to copy data table from data set to another data set.

DataSet ds = new DataSet();

ds = GetDataSet();

ds.Tables[0].TableName = "Old";

DataSet dsNew = new DataSet();

DataTable dt = ds.Tables[0];

ds.Tables.Remove(dt);

dt.TableName = "New";

dsNew.Tables.Add(dt);

Error : DataRow already belongs to another DataRow.

Copy data Row from one data table to another data table

DataTable dt = new DataTable();

Use ImportRow Instead of Row.Add (dt.Rows.Add(dataRow);)

dt.ImportRow(dataRow);

Get Updated Row state

This GetChanges method will give the updated row from original dataset.
And RowState method will give the state “Updated”,“Deleted”,”Inserted”

dsDataSet.GetChanges()
dsDataSet.Table[0].GetChages()
string updateMode = dsDataSet.Tables[0].Rows[rowNumber].RowState.ToString();

Create DataSet from DataRow.

private DataSet GetFilterChildRecords(DataSet dsMainDataSet,string whereCondition)

{

try

{

DataRow[] dr = dsMainDataSet.Tables[1].Select(whereCondition);

dsSetActCode_Details = dsMainDataSet.Clone();

for (int i = 0 ;i<dr.Length ;i++)

{

DataRow drNew = dsSetActCode_Details.Tables[1].NewRow();

dsSetActCode_Details.Tables[1].Rows.Add(drNew);

for (int j = 0; j < dr[i].ItemArray.Length; j++)

{

dsSetActCode_Details.Tables[1].Rows[i][j] = dr[i][j];

}

}

return dsSetActCode_Details;

}

catch(Exception Ex)

{

throw Ex;}

}