c# sql server连接（增、删、改、查）

C#和SQL Server连接可以使用ADO.NET技术实现，以下是增删改查的示例代码：

1. 增加数据：

using System.Data.SqlClient;

string connectionString = "Data Source=yourServerName;Initial Catalog=yourDatabaseName;Integrated Security=True";
string insertQuery = "INSERT INTO yourTableName (column1, column2) VALUES (@value1, @value2)";

using (SqlConnection connection = new SqlConnection(connectionString))
{
    SqlCommand command = new SqlCommand(insertQuery, connection);
    command.Parameters.AddWithValue("@value1", "someValue1");
    command.Parameters.AddWithValue("@value2", "someValue2");

    connection.Open();
    int rowsAffected = command.ExecuteNonQuery();
}

2. 删除数据：

using System.Data.SqlClient;

string connectionString = "Data Source=yourServerName;Initial Catalog=yourDatabaseName;Integrated Security=True";
string deleteQuery = "DELETE FROM yourTableName WHERE column1 = @value1";

using (SqlConnection connection = new SqlConnection(connectionString))
{
    SqlCommand command = new SqlCommand(deleteQuery, connection);
    command.Parameters.AddWithValue("@value1", "someValue1");

    connection.Open();
    int rowsAffected = command.ExecuteNonQuery();
}

3. 修改数据：

using System.Data.SqlClient;

string connectionString = "Data Source=yourServerName;Initial Catalog=yourDatabaseName;Integrated Security=True";
string updateQuery = "UPDATE yourTableName SET column1 = @value1 WHERE column2 = @value2";

using (SqlConnection connection = new SqlConnection(connectionString))
{
    SqlCommand command = new SqlCommand(updateQuery, connection);
    command.Parameters.AddWithValue("@value1", "newValue1");
    command.Parameters.AddWithValue("@value2", "someValue2");

    connection.Open();
    int rowsAffected = command.ExecuteNonQuery();
}

4. 查询数据：

using System.Data.SqlClient;

string connectionString = "Data Source=yourServerName;Initial Catalog=yourDatabaseName;Integrated Security=True";
string selectQuery = "SELECT * FROM yourTableName WHERE column1 = @value1";

using (SqlConnection connection = new SqlConnection(connectionString))
{
    SqlCommand command = new SqlCommand(selectQuery, connection);
    command.Parameters.AddWithValue("@value1", "someValue1");

    connection.Open();
    SqlDataReader reader = command.ExecuteReader();

    while (reader.Read())
    {
        // do something with the data
    }
}