Basic Database Operations Using C#
Last Updated :
31 Jan, 2023
In this article, you are going to learn about how to perform basic database operations using system.data.SqlClient namespace in C#. The basic operations are INSERT, UPDATE, SELECT and DELETE. Although the target database system is SQL Server Database, the same techniques can be applied to other database systems because the query syntax used is standard SQL that is generally supported by all relational database systems.
Prerequisites: Microsoft SQL Server Management Studio
Open Microsoft SQL Server Management Studio and write the below script to create a database and table in it.
create database Demodb;
use Demodb;
CREATE TABLE demo(
articleID varchar(30) NOT NULL PRIMARY KEY,
articleName varchar(30) NOT NULL,
);
insert into demo values(1, 'C#');
insert into demo values(2, 'C++');
After executing the above script following table named demo is created and it contains the following data as shown in the screenshot.
Connecting C# with Database: To work with a database, the first of all you required a connection. The connection to a database normally consists of the below-mentioned parameters.
- Database name or Data Source: The database name to which the connection needs to be set up and connection can be made or you can say only work with one database at a time.
- Credentials: The username and password which needs to be used to establish a connection to the database.
- Optional Parameters: For each database type, you can specify optional parameters to provide more information on how .NET should connect to the database to handle the data.
Note: Here, we are using command prompt to execute these codes. To see the result, you can use the Microsoft SQL Server Management Studio.
Code 1#: Connecting with database in C#
csharp
using System;
using System.Data.SqlClient;
namespace Database_Operation {
class DBConn {
static void Main()
{
Connect();
Console.ReadKey();
}
static void Connect()
{
string constr;
SqlConnection conn;
constr = @"Data Source=DESKTOP-GP8F496;Initial Catalog=Demodb;User ID=sa;Password=24518300";
conn = new SqlConnection(constr);
conn.Open();
Console.WriteLine("Connection Open!");
conn.Close();
}
}
}
|
Output:
Connection Open !
Code #2: Using Select Statement and SqlDataReader for accessing the data in C#
csharp
using System;
using System.Data.SqlClient;
namespace Database_Operation {
class SelectStatement{
static void Main()
{
Read();
Console.ReadKey();
}
static void Read()
{
string constr;
SqlConnection conn;
constr = @"Data Source=DESKTOP-GP8F496;Initial Catalog=Demodb;User ID=sa;Password=24518300";
conn = new SqlConnection(constr);
conn.Open();
SqlCommand cmd;
SqlDataReader dreader;
string sql, output = "";
sql = "Select articleID, articleName from demo";
cmd = new SqlCommand(sql, conn);
dreader = cmd.ExecuteReader();
while (dreader.Read()) {
output = output + dreader.GetValue(0) + " - " +
dreader.GetValue(1) + "\n";
}
Console.Write(output);
dreader.Close();
cmd.Dispose();
conn.Close();
}
}
}
|
Output:
1 - C#
2 - C++
Code #3: Inserting the data into the database using Insert Statement in C#
csharp
using System;
using System.Data.SqlClient;
namespace Database_Operation {
class InsertStatement {
static void Main()
{
Insert();
Console.ReadKey();
}
static void Insert()
{
string constr;
SqlConnection conn;
constr = @"Data Source=DESKTOP-GP8F496;Initial Catalog=Demodb;User ID=sa;Password=24518300";
conn = new SqlConnection(constr);
conn.Open();
SqlCommand cmd;
SqlDataAdapter adap = new SqlDataAdapter();
string sql = "";
sql = "insert into demo values(3, 'Python')";
cmd = new SqlCommand(sql, conn);
adap.InsertCommand = new SqlCommand(sql, conn);
adap.InsertCommand.ExecuteNonQuery();
cmd.Dispose();
conn.Close();
}
}
}
|
Output:
Code #4: Updating the data into the database using Update Statement in C#
csharp
using System;
using System.Data.SqlClient;
namespace Database_Operation {
class UpdateStatement {
static void Main()
{
Update();
Console.ReadKey();
}
static void Update()
{
string constr;
SqlConnection conn;
constr = @"Data Source=DESKTOP-GP8F496;Initial Catalog=Demodb;User ID=sa;Password=24518300";
conn = new SqlConnection(constr);
conn.Open();
SqlCommand cmd;
SqlDataAdapter adap = new SqlDataAdapter();
string sql = "";
sql = "update demo set articleName='django' where articleID=3";
cmd = new SqlCommand(sql, conn);
adap.InsertCommand = new SqlCommand(sql, conn);
adap.InsertCommand.ExecuteNonQuery();
cmd.Dispose();
conn.Close();
}
}
}
|
Output:
Code #5: Deleting the data into the database using Delete Statement in C#
csharp
using System;
using System.Data.SqlClient;
namespace Database_Operation {
class DeleteStatement {
static void Main()
{
Delete();
Console.ReadKey();
}
static void Delete()
{
string constr;
SqlConnection conn;
constr = @"Data Source=DESKTOP-GP8F496;Initial Catalog=Demodb;User ID=sa;Password=24518300";
conn = new SqlConnection(constr);
conn.Open();
SqlCommand cmd;
SqlDataAdapter adap = new SqlDataAdapter();
string sql = "";
sql = "delete from demo where articleID=3";
cmd = new SqlCommand(sql, conn);
adap.InsertCommand = new SqlCommand(sql, conn);
adap.InsertCommand.ExecuteNonQuery();
cmd.Dispose();
conn.Close();
}
}
}
|
Output:
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