c# 操作sqlserver 增删改查

以下是使用 C# 操作 SQL Server 的增删改查示例：

1. 连接数据库

using System.Data.SqlClient;

string connectionString = "Data Source=(local);Initial Catalog=databaseName;Integrated Security=True";
SqlConnection connection = new SqlConnection(connectionString);
connection.Open();

2. 插入数据

string insertQuery = "INSERT INTO tableName (column1, column2, column3) VALUES (@value1, @value2, @value3)";
SqlCommand command = new SqlCommand(insertQuery, connection);
command.Parameters.AddWithValue("@value1", "value1");
command.Parameters.AddWithValue("@value2", "value2");
command.Parameters.AddWithValue("@value3", "value3");
command.ExecuteNonQuery();

3. 查询数据

string selectQuery = "SELECT * FROM tableName";
SqlCommand command = new SqlCommand(selectQuery, connection);
SqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
    string column1Value = reader.GetString(0);
    string column2Value = reader.GetString(1);
    string column3Value = reader.GetString(2);
    // 输出或处理查询结果
}

4. 更新数据

string updateQuery = "UPDATE tableName SET column1 = @value1 WHERE column2 = @value2";
SqlCommand command = new SqlCommand(updateQuery, connection);
command.Parameters.AddWithValue("@value1", "newValue1");
command.Parameters.AddWithValue("@value2", "value2");
command.ExecuteNonQuery();

5. 删除数据

string deleteQuery = "DELETE FROM tableName WHERE column2 = @value2";
SqlCommand command = new SqlCommand(deleteQuery, connection);
command.Parameters.AddWithValue("@value2", "value2");
command.ExecuteNonQuery();

6. 关闭连接

connection.Close();