Sql Server助手类
//拷贝时请注意文件的定义名称要一致
namespace DAL
{
public class SQLHelper
{
//定义一个连接字符串
string connstr = ConfigurationManager.ConnectionStrings["Constr"].ConnectionString;
#region 执行非查询语句,返回受影响的行数
/// <summary>
/// 执行非查询语句,返回受影响的行数
/// </summary>
/// <param name="sql"></param>
/// <param name="ct"></param>
/// <param name="parameters"></param>
/// <returns></returns>
public int ExecuteNonQuery(string sql, CommandType ct, params SqlParameter[] parameters)
{
using (SqlConnection conn = new SqlConnection(connstr))
{
conn.Open();
using (SqlCommand cmd = conn.CreateCommand())
{
cmd.CommandText = sql;
cmd.CommandType = ct;
foreach (SqlParameter parameter in parameters)
{
cmd.Parameters.Add(parameter);
}
return cmd.ExecuteNonQuery();
}
}
}
#endregion
#region 执行sql语句,返回第一行第一列的值
/// <summary>
/// 执行SQL语句,返回第一行第一列的值,因为不知道类型,所以用Object
/// </summary>
/// <param name="sql"></param>
/// <param name="ct"></param>
/// <param name="parameters"></param>
/// <returns></returns>
public object ExecuteScalar(string sql, CommandType ct, params SqlParameter[] parameters)
{
using (SqlConnection conn = new SqlConnection(connstr))
{
conn.Open();
using (SqlCommand cmd = conn.CreateCommand())
{
cmd.CommandText = sql;
cmd.CommandType = ct;
foreach (SqlParameter parameter in parameters)
{
cmd.Parameters.Add(parameter);
}
return cmd.ExecuteScalar();
}
}
}
#endregion
#region 执行sql语句,返回一个表
/// <summary>
/// 执行sql语句,返回一个表
/// </summary>
/// <param name="sql"></param>
/// <param name="ct"></param>
/// <param name="parameters"></param>
/// <returns></returns>
public DataTable ExecuteDataTable(string sql, CommandType ct, params SqlParameter[] parameters)
{
using (SqlConnection conn = new SqlConnection(connstr))
{
conn.Open();
using (SqlCommand cmd = conn.CreateCommand())
{
cmd.CommandText = sql;
cmd.CommandType = ct;
foreach (SqlParameter parameter in parameters)
{
cmd.Parameters.Add(parameter);
}
DataSet ds = new DataSet();
SqlDataAdapter adapter = new SqlDataAdapter(cmd);
adapter.Fill(ds);
return ds.Tables[0];
}
}
}
#endregion
}
}