用C#连接数据库 创建疫苗表(编号、名称、注射量、保质期、价格)； 添加5条测试数据 实现增删改查

以下是用C#连接数据库创建疫苗表(编号、名称、注射量、保质期、价格)；添加5条测试数据并实现增删改查的示例代码：

using System;
using System.Data.SqlClient;

namespace VaccineManagement
{
    class Program
    {
        static void Main(string[] args)
        {
            string connectionString = "Data Source=(localdb)\\MSSQLLocalDB;Initial Catalog=VaccineDB;Integrated Security=True;";
            
            // 创建疫苗表
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();
                string createTableQuery = "CREATE TABLE Vaccine (Id INT PRIMARY KEY IDENTITY, Name VARCHAR(50), Dosage INT, ShelfLife INT, Price DECIMAL(10, 2))";
                SqlCommand command = new SqlCommand(createTableQuery, connection);
                command.ExecuteNonQuery();
            }
            
            // 添加测试数据
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();
                string insertQuery = "INSERT INTO Vaccine (Name, Dosage, ShelfLife, Price) VALUES (@Name, @Dosage, @ShelfLife, @Price)";
                SqlCommand command = new SqlCommand(insertQuery, connection);
                command.Parameters.AddWithValue("@Name", "疫苗A");
                command.Parameters.AddWithValue("@Dosage", 2);
                command.Parameters.AddWithValue("@ShelfLife", 365);
                command.Parameters.AddWithValue("@Price", 100);
                command.ExecuteNonQuery();
                command.Parameters.Clear();
                command.Parameters.AddWithValue("@Name", "疫苗B");
                command.Parameters.AddWithValue("@Dosage", 3);
                command.Parameters.AddWithValue("@ShelfLife", 180);
                command.Parameters.AddWithValue("@Price", 200);
                command.ExecuteNonQuery();
                command.Parameters.Clear();
                command.Parameters.AddWithValue("@Name", "疫苗C");
                command.Parameters.AddWithValue("@Dosage", 1);
                command.Parameters.AddWithValue("@ShelfLife", 90);
                command.Parameters.AddWithValue("@Price", 50);
                command.ExecuteNonQuery();
                command.Parameters.Clear();
                command.Parameters.AddWithValue("@Name", "疫苗D");
                command.Parameters.AddWithValue("@Dosage", 4);
                command.Parameters.AddWithValue("@ShelfLife", 365);
                command.Parameters.AddWithValue("@Price", 300);
                command.ExecuteNonQuery();
                command.Parameters.Clear();
                command.Parameters.AddWithValue("@Name", "疫苗E");
                command.Parameters.AddWithValue("@Dosage", 2);
                command.Parameters.AddWithValue("@ShelfLife", 180);
                command.Parameters.AddWithValue("@Price", 150);
                command.ExecuteNonQuery();
            }
            
            // 查询疫苗信息
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();
                string selectQuery = "SELECT * FROM Vaccine";
                SqlCommand command = new SqlCommand(selectQuery, connection);
                SqlDataReader reader = command.ExecuteReader();
                while (reader.Read())
                {
                    Console.WriteLine($"编号: {reader["Id"]}, 名称: {reader["Name"]}, 注射量: {reader["Dosage"]}, 保质期: {reader["ShelfLife"]}, 价格: {reader["Price"]}");
                }
                reader.Close();
            }
            
            // 更新疫苗信息
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();
                string updateQuery = "UPDATE Vaccine SET Price = @Price WHERE Name = @Name";
                SqlCommand command = new SqlCommand(updateQuery, connection);
                command.Parameters.AddWithValue("@Name", "疫苗B");
                command.Parameters.AddWithValue("@Price", 250);
                int rowsAffected = command.ExecuteNonQuery();
                Console.WriteLine($"{rowsAffected} 行受影响");
            }
            
            // 查询更新后的疫苗信息
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();
                string selectQuery = "SELECT * FROM Vaccine WHERE Name = @Name";
                SqlCommand command = new SqlCommand(selectQuery, connection);
                command.Parameters.AddWithValue("@Name", "疫苗B");
                SqlDataReader reader = command.ExecuteReader();
                while (reader.Read())
                {
                    Console.WriteLine($"编号: {reader["Id"]}, 名称: {reader["Name"]}, 注射量: {reader["Dosage"]}, 保质期: {reader["ShelfLife"]}, 价格: {reader["Price"]}");
                }
                reader.Close();
            }
            
            // 删除疫苗信息
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();
                string deleteQuery = "DELETE FROM Vaccine WHERE Name = @Name";
                SqlCommand command = new SqlCommand(deleteQuery, connection);
                command.Parameters.AddWithValue("@Name", "疫苗D");
                int rowsAffected = command.ExecuteNonQuery();
                Console.WriteLine($"{rowsAffected} 行受影响");
            }
            
            // 查询删除后的疫苗信息
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();
                string selectQuery = "SELECT * FROM Vaccine";
                SqlCommand command = new SqlCommand(selectQuery, connection);
                SqlDataReader reader = command.ExecuteReader();
                while (reader.Read())
                {
                    Console.WriteLine($"编号: {reader["Id"]}, 名称: {reader["Name"]}, 注射量: {reader["Dosage"]}, 保质期: {reader["ShelfLife"]}, 价格: {reader["Price"]}");
                }
                reader.Close();
            }
        }
    }
}

注意，上述示例代码使用的数据库为本地 SQL Server Express LocalDB 实例，需要先安装 SQL Server Express LocalDB，并且连接字符串中的 Initial Catalog 参数指定了创建的数据库名称为 VaccineDB。如果使用其他数据库或者 SQL Server 实例，请相应更改连接字符串。