This document provides an overview of ADO.net and how it can be used to connect front-end applications like C# to back-end databases. It discusses the key classes and components in ADO.net like Connection, Command, DataAdapter and DataSet. It provides examples of performing basic CRUD operations on databases using both connection-oriented and disconnected models. It also demonstrates how to retrieve and display data in controls like DataGridView and bind related tables using DataRelations in a DataSet.

1. Hi friends
C# Tutorial
Part 37:ADO.net
www.siri-kt.blogspot.com

2. • ADO is nothing but active x data objects. we can communicate
between front end to backend using ado.net
• Front end is nothing but c#.net, vb.net, Asp.net etc
• Back end is nothing but database sql server, oracle, ms-access, ms-
excel
• ADO.net supports different providers
• 1.using system.data.sqlclient;
• 2.using system.data.oracleclient;
• 3.using system.data.odbc;(ms-access,ms-excel);
• 4.using system.data.oledb;(sqlserver & oracle);
• odbc-open database connectivity. oledb-object linked embedded
database
• ado.net supports 2 types of connection models:
• 1.connection oriented model

3. • 1.connection oriented model: in this model front end to Back end
directly relation is possible. connection flow:
• connection-con.open()-command-UI
• 1.connection: this class establishes the communication bw front end
to backend.
• this class supports 2 methods
• 1.open():using this method we can open the established connection
way.
• 2.close(): using this method we can close the opened connection way.
• command class:
• this class is used to send sql statement request from the f.e
• and for getting the response.
• this class supports 2 parameters
• 1.sql statements

4. • This class supports 3 methods
• 1.executenonquery()-insert,update,delete statements
• 2.executescalar()-authentication logic
• 3.executeReader()-Readonly data,forward the records.this
method
• Returns datareader class.
• Data reader class supports 2 methods
• 1.Read()
• 2.close()
• Example on connection oriented model:
• 1.take the form
• 2.add 3 labels,3 textboxes and 3 buttons

5. • using System.Data.SqlClient;
• private void button1_Click(object sender, EventArgs e)
• { SqlConnection con = new SqlConnection("data source=sit-pc;database=suhashini;user
id=sa;password=123");
• con.Open();
• SqlCommand cmd = new SqlCommand("insert into student values(" + textBox1.Text + ",'" +
textBox2.Text + "','" + textBox3.Text + "')", con);
• cmd.ExecuteNonQuery();
• MessageBox.Show("values are inserted"); }
• private void button2_Click(object sender, EventArgs e)
• { SqlConnection con = new SqlConnection("data source=sit-pc;database=suhashini;user
id=sa;password=123");
• con.Open();
• SqlCommand cmd = new SqlCommand("update student set sname='" + textBox2.Text + "',saddress='" +
textBox3.Text + "' where sno=" + textBox1.Text, con);
• cmd.ExecuteNonQuery();
• MessageBox.Show("values are updated"); }
• private void button3_Click(object sender, EventArgs e)
• { SqlConnection con = new SqlConnection("data source=sit-pc;database=suhashini;user
id=sa;password=123");
• con.Open();
• SqlCommand cmd = new SqlCommand("delete from student where sno=" + textBox1.Text, con);

6. • Example on connection oriented in oledb:
• 1.take the form
• 2.add 3 labels,3 textboxes and 3 buttons
• source code:
• using System.Data.OleDb;
• private void button1_Click(object sender, EventArgs e)
• { OleDbConnection con = new
OleDbConnection("provider=sqloledb.1;data source=sit-
pc;database=suhashini;user id=sa;password=123");
• con.Open();
• OleDbCommand cmd = new OleDbCommand("insert into student
values(" + textBox1.Text + ",'" + textBox2.Text + "','" + textBox3.Text +
"')", con);
• cmd.ExecuteNonQuery();
• MessageBox.Show("values are inserted");

7. • private void button2_Click(object sender, EventArgs e)
• { OleDbConnection con = new
OleDbConnection("provider=sqloledb.1;data source=sit-
pc;database=suhashini;user id=sa;password=123");
• con.Open();
• OleDbCommand cmd = new OleDbCommand("update student set
sname='" + textBox2.Text + "',saddress='" + textBox3.Text + "' where
sno=" + textBox1.Text, con);
• cmd.ExecuteNonQuery();
• MessageBox.Show("values are updated"); }
• private void button3_Click(object sender, EventArgs e)
• { OleDbConnection con = new
OleDbConnection("provider=sqloledb.1;data source=sit-
pc;database=suhashini;user id=sa;password=123");
• con.Open();
• OleDbCommand cmd = new OleDbCommand("delete from student
where sno=" + textBox1.Text, con);
• cmd.ExecuteNonQuery();

8. • disconnection model:
• In the disconnection model front end to back end
directly relation is not possible . we can bridge the
communication between front end to back end using data
adapter.
• disconnection flow:
• connection-data adapter-dataset-da.fill(ds,dt)-ui
• data bounded controls:
• using this controls back end data base values bind with
the front end
• displayed in tabular format.

9. • c#.net supports no of data bounded controls
• 1.datagridview
• 2.dataset
• 3.datagrid
• example on disconnection flow:
• 1.take the form
• 2.add datagridview control
• 3.add button control
• using System.Data.SqlClient;
• private void button1_Click(object sender, EventArgs e)
• { SqlConnection con = new SqlConnection("data source=sit-
pc;database=suhashini;user id=sa;password=123");
• SqlDataAdapter da = new SqlDataAdapter("select * from student", con);
• DataSet ds = new DataSet();
• da.Fill(ds);
• dataGridView1.DataSource = ds.Tables[0]; }

10. • example on datareader class:
• 1.take the form
• 2.add 3 labels,3 textboxes,3 buttons
• source code:
• SqlConnection con = new SqlConnection("data source=sit-pc;database=suhashini;user
id=sa;password=123");
• SqlCommand cmd;
• SqlDataReader dr;
• private void button1_Click(object sender, EventArgs e)
• { con.Open();
• cmd = new SqlCommand("select * from student", con);
• dr = cmd.ExecuteReader();
• dr.Read();
• textBox1.Text = dr[0].ToString();
• textBox2.Text = dr[1].ToString();
• textBox3.Text = dr[2].ToString(); }

11. • private void button2_Click(object sender, EventArgs e)
• { if (dr.Read())
• { textBox1.Text = dr[0].ToString();
• textBox2.Text = dr[1].ToString();
• textBox3.Text = dr[2].ToString();
• } else
• { MessageBox.Show("EOR");
• } }
• Dataadapter:
• it is bridge the communication between front end to back end
• this class having 2 parameters
• 1.select statement
• 2.connection object

12. • methods:
• 1.fill(ds,dt):retrieve the data from dataset
• syntax:
• da.fill(ds,dt)
• ds=dataset
• dt=datatable
• 2.update(ds,dt)
• syntax:
• da.updat(ds,dt)
• ds=dataset
• dt=datatable

13. • Datagridview:
• this control supports a only single table at a time
• Datagrid:
• this control supports multiple tables at a time. this control supports primary key and
foriegn key tables
• example on datagrid control:
• 1.take the form
• 2.add datagrid control
• source code:
• using System.Data.SqlClient;
• private void button1_Click(object sender, EventArgs e)
• { SqlConnection con = new SqlConnection("data source=sit-
pc;database=suhashini;user id=sa;password=123");
• SqlDataAdapter da1 = new SqlDataAdapter("select * from dept", con);
• SqlDataAdapter da2 = new SqlDataAdapter("select * from emp", con);
• DataSet ds = new DataSet(); da1.Fill(ds, "d"); da2.Fill(ds,"e");
dataGrid1.DataSource = ds;

14. • commandbuilder :
• This class is used to generate sql statements this class takes columns information from
data adapter
• This class supports 3 methods
• 1.GetInsertCommand()
• 2.GetUpdatecommand()
• 3.GetDeletecommand()
• 1.GetInsertcommand(): this method generates insert sql statements
• syntax: da.insertcommand=cmb.Getinsertcommand();
• 2.GetUpadatecommand(): this method generates update sql statements
• syntax: da.updatecommand=cmb.getupdatecommand();
• 3.GetDeletecommand():this method generates delete sql statements
• da.deletecommand=cmb.getdeletecommand();

15. • Example on Commandbuilder:
• 1.take the 1 form
• 2.add datagrid control
• 3.add 3 labels ,3 textboxes and 3 buttons
• Source Code:
• SqlConnection con = new SqlConnection("data source=sit-pc;database=suhashini;user
id=sa;password=123");
• SqlDataAdapter da;
• DataSet ds = new DataSet();
• DataTable dt = new DataTable();
• DataRow dr;
• SqlCommandBuilder cmb;
• private void button1_Click(object sender, EventArgs e)
• { da = new SqlDataAdapter("select * from student", con);
• da.Fill(ds, "s"); dt = ds.Tables["s"]; dataGrid1.DataSource = dt;
• }

16. • private void button2_Click(object sender, EventArgs e)
• { da = new SqlDataAdapter("select * from student",
con);
• cmb = new SqlCommandBuilder(da);
• dr = dt.NewRow();
• dr["sno"] = Convert.ToInt16(textBox1.Text);
• dr["sname"] = textBox2.Text; dr["saddress"] =
textBox3.Text;
• dt.Rows.Add(dr); da.InsertCommand =
cmb.GetInsertCommand();
• da.Update(ds, "s");
• }
• private void button3_Click(object sender, EventArgs e)
• { da = new SqlDataAdapter("select * from student",
con);
• cmb = new SqlCommandBuilder(da);
• da.UpdateCommand = cmb.GetUpdateCommand();

17. • Dataset using data relation:
• While creating relations in the dataset at least we have
to work with 2 –tables while creating the tables we
have to create tables with primary key constraint & with
foreign key constraint
• which table having primary key constraint column that
table is master table. which table having foreign key
constraint column that that table is child table.
• master table:
• dept
• dno int(primary key)
• dname varchar(50)
• daddress varchar(50)

18. • Emp
• eno int
• ename varchar(50)
• dno int (foreign key)
• Data Relation:
• this class is used to generate relations in the dataset. this class
takes 3 constructor parameters
• 1.Relation name
• 2. Primary key constraint column
• 3. foreign key constraint column

19. • example on data relation:
• 1.take the form
• 2.Add datagrid control
• 3.add 1 button control
• source code:
• SqlConnection con = new SqlConnection("data source=sit-pc;database=suhashini;user
id=sa;password=123");
• SqlDataAdapter da1, da2;
• DataSet ds = new DataSet();
• DataRelation dr;
• private void button1_Click(object sender, EventArgs e)
• { da1 = new SqlDataAdapter("select * from dept", con);
• da2 = new SqlDataAdapter("select * from emp", con);
• da1.Fill(ds, "d"); da2.Fill(ds, "e");
• DataColumn pk = ds.Tables["d"].Columns["dno"]; DataColumn fk =
ds.Tables["e"].Columns["dno"];
• dr = new DataRelation("rel", pk, fk); ds.Relations.Add(dr);
dataGrid1.DataSource = ds;

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