C# 封装SqlHelper

老师在讲C#实战项目时所使用的SqlHelper，使用的数据库是SQL Server

注意，连接数据库的连接字符串需要在配置文件中设置好

<appSettings>
    <add key = "connString" value="data source = .; database = CourseSelectionInfo; integrated security = true"/>
</appSettings>

public class SqlHelper
{
#region 连接字符串connString
private static string connString;
static SqlHelper()
{
connString = ConfigurationManager.AppSettings["connString"];
}
#endregion
#region 增删改int ExcuteNonQuery(string cmdText, CommandType cmdType, params SqlParameter[] parameters)
/// <summary>
/// 增删改
/// </summary>
/// <param name="cmdText">sql</param>
/// <param name="cmdType"></param>
/// <param name="parameters">参数</param>
/// <returns>修改了几行</returns>
public static int ExcuteNonQuery(string cmdText, CommandType cmdType, params SqlParameter[] parameters)
{
using (SqlConnection connection = new SqlConnection(connString))
{
using (SqlCommand cmd = new SqlCommand(cmdText, connection))
{
cmd.CommandType = cmdType;
connection.Open();
if (parameters.Length > 0)
{
cmd.Parameters.AddRange(parameters);
}
return cmd.ExecuteNonQuery();
}
}
}
#endregion
#region 获取一个数据 T ExcuteScalar<T>(string cmdText,  CommandType cmdType, params SqlParameter[] parameters)
/// <summary>
/// 获取一个数据<T>
/// </summary>
/// <typeparam name="T">数据类型</typeparam>
/// <param name="cmdText">sql</param>
/// <param name="cmdType"></param>
/// <param name="parameters">参数</param>
/// <returns>任意类型的数据</returns>
public static T ExcuteScalar<T>(string cmdText, CommandType cmdType, params SqlParameter[] parameters)
{
using (SqlConnection connection = new SqlConnection(connString))
{
using (SqlCommand cmd = new SqlCommand(cmdText, connection))
{
cmd.CommandType = cmdType;
connection.Open();
if (parameters.Length > 0)
{
cmd.Parameters.AddRange(parameters);
}
return (T)cmd.ExecuteScalar();
}
}
}
#endregion
#region 读取数据表SqlDataReader ExcuteReader(string cmdText, CommandType cmdType, params SqlParameter[] parameters)
/// <summary>
/// 读取数据表
/// </summary>
/// <param name="cmdText">sql</param>
/// <param name="cmdType"></param>
/// <param name="parameters">参数</param>
/// <returns>SqlDataReader</returns>
public static SqlDataReader ExcuteReader(string cmdText, CommandType cmdType, params SqlParameter[] parameters)
{
SqlConnection connection = new SqlConnection(connString);
using (SqlCommand cmd = new SqlCommand(cmdText, connection))
{
cmd.CommandType = cmdType;
connection.Open();
if (parameters.Length > 0)
{
cmd.Parameters.AddRange(parameters);
}
return cmd.ExecuteReader(CommandBehavior.CloseConnection);
}
}
#endregion
#region 临时数据库DataSet GetDataSet(string cmdText, CommandType cmdType, params SqlParameter[] parameters)
/// <summary>
/// 获取临时数据库
/// </summary>
/// <param name="cmdText"></param>
/// <param name="cmdType"></param>
/// <param name="parameters"></param>
/// <returns></returns>
public static DataSet GetDataSet(string cmdText, CommandType cmdType, params SqlParameter[] parameters)
{
DataSet ds = new DataSet();
using (SqlConnection connection = new SqlConnection(connString))
{
using (SqlCommand cmd = new SqlCommand(cmdText, connection))
{
cmd.CommandType = cmdType;
using (SqlDataAdapter adapter = new SqlDataAdapter(cmd))
{
if (parameters.Length > 0)
{
adapter.SelectCommand.Parameters.AddRange(parameters);
}
adapter.Fill(ds);
}
}
}
return ds;
}
#endregion
#region 临时数据表DataTable GetDataTable(string cmdText, CommandType cmdType, params SqlParameter[] parameters)
/// <summary>
/// 获取临时数据表
/// </summary>
/// <param name="cmdText">sql</param>
/// <param name="cmdType"></param>
/// <param name="parameters">参数</param>
/// <returns></returns>
public static DataTable GetDataTable(string cmdText, CommandType cmdType, params SqlParameter[] parameters)
{
return GetDataSet(cmdText, cmdType, parameters).Tables[0];
}
#endregion
}

本文地址：https://blog.csdn.net/weixin_43783363/article/details/107135152