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  • 自己整理的的数据操作DbHelper

    using System.Data;
    using System.Data.SqlClient;
    using System.Configuration;
    
    namespace WindowsFormsApp3
    {
        public class DbHelper
        {
            private static string connStr = ConfigurationManager.ConnectionStrings["Demo"].ToString();
    
            /// <summary>
            /// 根据Sql语句返回Table类型数据
            /// </summary>
            /// <param name="sql">查询Sql语句</param>
            /// <returns>Table</returns>
            /// <SqlParameter>SqlParameter</SqlParameter>
            public static DataTable GetDataTable(string sql, SqlParameter[] sqlParameter = null)
            {
                DataSet ds = new DataSet();
                using (SqlConnection sqlConn = new SqlConnection(connStr))
                {
                    sqlConn.Open();
                    if (sqlConn.State == ConnectionState.Open)
                    {
                        using (SqlCommand cmd = new SqlCommand(sql, sqlConn))
                        {
                            if (sqlParameter != null && sqlParameter.Length > 0)
                                cmd.Parameters.AddRange(sqlParameter);
                            SqlDataAdapter da = new SqlDataAdapter(cmd);
                            da.Fill(ds);
                        }
                    }
                }
                return ds.Tables[0];
            }
    
            /// <summary>
            /// 查询数据库是否存在数据
            /// </summary>
            /// <param name="sql">查询Sql语句</param>
            /// <param name="sqlParameter">查询参数</param>
            /// <returns>存在返回True,不存在返回False</returns>
            public static bool DataIsHasRows(string sql, SqlParameter[] sqlParameter = null)
            {
                bool HasRows = false;
                using (SqlConnection sqlConn = new SqlConnection(connStr))
                {
                    sqlConn.Open();
                    if (sqlConn.State == ConnectionState.Open)
                    {
                        using (SqlCommand cmd = new SqlCommand(sql, sqlConn))
                        {
                            if (sqlParameter != null && sqlParameter.Length > 0)
                                cmd.Parameters.AddRange(sqlParameter);
                            using (SqlDataReader dr = cmd.ExecuteReader())
                            {
                                if (dr.HasRows)
                                {
                                    HasRows = true;
                                }
                            }
                        }
                    }
                }
                return HasRows;
            }
            /// <summary>
            /// 执行Sql语句返回受影响行数
            /// </summary>
            /// <param name="sql">Sql语句</param>
            /// <param name="sqlParameter">Sql参数</param>
            /// <returns>返回受影响行数</returns>
            public static int ExecNonQuery(string sql, SqlParameter[] sqlParameter =null)
            {
                int num = 0;
                try
                {
                    using (SqlConnection sqlConn = new SqlConnection(connStr))
                    {
                        sqlConn.Open();
                        if (sqlConn.State == ConnectionState.Open)
                        {
                            using (SqlCommand cmd = new SqlCommand(sql, sqlConn))
                            {
                                if (sqlParameter != null && sqlParameter.Length > 0)
                                    cmd.Parameters.AddRange(sqlParameter);
                                num = cmd.ExecuteNonQuery();
                            }
                        }
                    }
                    return num;
                }
                catch
                {
                    return -1;
                }
    
            }
            /// <summary>
            /// 返回第一行第一列内容
            /// </summary>
            /// <param name="sql"></param>
            /// <param name="sqlParameters"></param>
            /// <returns></returns>
            public static string ExecScalar(string sql, SqlParameter[] sqlParameter = null)
            {
                string value = "";
                using (SqlConnection sqlConn = new SqlConnection(connStr))
                {
                    sqlConn.Open();
                    if (sqlConn.State == ConnectionState.Open)
                    {
                        using (SqlCommand cmd = new SqlCommand(sql, sqlConn))
                        {
                            if (sqlParameter != null && sqlParameter.Length > 0)
                                cmd.Parameters.AddRange(sqlParameter);
                            value = cmd.ExecuteScalar().ToString();
                        }
                    }
                }
                return value;
            }
        }
    }
    App.config
    <?xml version="1.0" encoding="utf-8" ?>
    <configuration>
        <startup> 
            <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.2" />
        </startup>
      <connectionStrings>
        <add name="Demo" connectionString="Data Source=127.0.0.1;Initial Catalog=AdventureWorks;Persist Security Info=True;User ID=sa;Password=Sa123"/>
      </connectionStrings>
    </configuration>
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  • 原文地址:https://www.cnblogs.com/liessay/p/11866859.html
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