| Author: sivapriya 28 Aug 2008 | Member Level: Gold | Rating:  Points: 5 |
In Typed dataset we can know the schema of table at compile time itself.
But in normal dataset we can know the schema at run time only..
u can retrive the value like
ds.tables[0].Rows[0]["columnname"].tostring();--normal dataset
in case of typed dataset
ds.tables[0].Rows[0].columnname.tostring()
For further go through:
http://www.c-sharpcorner.com/UploadFile/rupadhyaya/TypedDataSets12032005021013AM/TypedDataSets.aspx
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| Author: chandramohan 29 Aug 2008 | Member Level: Gold | Rating: Points: 2 |
data set is in memoery database of the client application..it is disconnected archtecture..it is supported an xml.
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| Author: Legend 29 Aug 2008 | Member Level: Silver | Rating: Points: 6 |
Introduction
As all of we know, we can specify the Data type when we create a DataColumn for a DataTable. This is to enforce the runtime Type-safety for the column so that only data of specified data type can be stored in the column. In the same way, in most of the cases we prefer to make a DataSet itself as Type-safe so as to protect it from runtime mismatch. Hence Typed DataSets generate classes that expose each object the in the DataSet in Type-safe manner. These classes inherits directly from DataSet class.
Let us look into a small example which explain the Typed DataSet,
1. Using DataSet:
//Create DataAdapter
SqlDataAdapter daEmp = new SqlDataAdapter("SELECT empno,empname,empaddress FROM EMPLOYEE",conn);
//Create a DataSet Object
DataSet dsEmp = new DataSet();
//Fill the DataSet
daEmp.Fill(dsEmp,"EMPLOYEE");
//Let us print first row and first column of the table
Console.Write(dsEmp.Tables["EMPLOYEE"].Rows[0][0].ToString());
//Assign a value to the first column
dsEmp.Tables["EMPLOYEE"].Rows[0][0] = "12345";//This will generate runtime error as empno column is integer
If we observe above code we will get a runtime error when this code gets executed as the value assigned to the column (empno) does not take string value. Also any misspell of the column will generate a runtime error. And also we need to go thro the hierarchy to get the final value.
2. Using Typed DataSet:
//Create DataAdapter
SqlDataAdapter daEmp = new SqlDataAdapter("SELECT empno,empname,empaddress FROM EMPLOYEE",conn);
//Create a DataSet Object
EmployeeDS dsEmp = new EmployeeDS ();
//Fill the DataSet
daEmp.Fill(dsEmp,"EMPLOYEE");
//Let us print first row and first column of the table
Console.Write(dsEmp.EMPLOYEE[0].empno.ToString());
//Assign a value to the first column
dsEmp.EMPLOYEE[0].empno = "12345";//This will generate compile time error.
If we see above code, a typed dataset is very much similar to a normal dataset. But the only difference is that the sehema is already present for the same. Hence any mismatch in the column will generate compile time errors rather than runtime error as in the case of normal dataset. Also accessing the column value is much easier than the normal dataset as the column definition will be available in the schema.
How to Generate Typed DataSet?
A Typed DataSet can be generated in two ways,
Using Visual Studio .NET IDE.
Using XSD.exe (Using VS.Net command prompt)
Open VS.Net command prompt and Type XSD /? For the help on this exe.
Creating a Typed DataSet using Visual Studio .NET IDE
if you want more
Please refer this URL(U better refer this link, url Explains with picture)
http://www.c-sharpcorner.com/UploadFile/rupadhyaya/TypedDataSets12032005021013AM/TypedDataSets.aspx
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