C# ADO.NET (sql语句连接方式)(查询)

时间:2021-12-03 17:15:38
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlClient;

namespace CMS.Admin
{
    public partial class select : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            string sql = "select * from [Column] where ColumnId in (@number1,@number2)"; //带参数的sql语句
            SqlParameter[] p = ]; //定义sql语句的参数数组
            p[] = new SqlParameter("@number1", SqlDbType.Int); //定义参数的数据类型
            p[] = new SqlParameter("@number2", SqlDbType.Int); //定义参数的数据类型
            p[].Value = ; //赋值
            p[].Value = ; //赋值
            DataTable data = QuerySql(sql, p); //调用数据库查询方法,获取 DataTable 数据
            foreach (DataRow row in data.Rows) //遍历 DataTable 中的具体数据
            {
                foreach (DataColumn column in data.Columns)
                {
                    Response.Write(row[column]);
                }
            }
        }

        /// <summary>
        /// 获取配置的数据库连接字符转
        /// </summary>
        public static string ConnStr
        {
            get
            {
                return System.Configuration.ConfigurationManager.ConnectionStrings["SQLConnectionString"].ConnectionString.ToString();
            }
        }

        /// <summary>
        /// 执行数据库查询
        /// </summary>
        /// <param name="sql">带或不带参数的sql语句</param>
        /// <param name="parm">sql语句的参数数组</param>
        /// <returns>查询结果(数据表对象)</returns>
        public static DataTable QuerySql(string sql, SqlParameter[] par)
        {
            SqlConnection conn = new SqlConnection(ConnStr); //实例化数据库连接对象
            SqlDataAdapter sda = new SqlDataAdapter(sql, conn); //实例化数据库识别器对象
            )  //给数据库识别对象赋予参数
            {
                foreach (SqlParameter p in par)
                {
                    sda.SelectCommand.Parameters.Add(p);
                }
            }
            DataTable data = new DataTable(); //定义表数据
            sda.Fill(data);  //填充数据表
            return data;
        }
    }
}