分享一个简单的C#的通用DbHelper类（支持数据连接池）

每次新项目的时候，都要从头去找一遍数据库工具类。这里分享一个简单实用的C#的通用DbHelper工具类，支持数据连接池。

连接池配置

<connectionStrings>
　　<add name="dh_web" connectionString="Data Source=xxx.com;Initial Catalog=xx_db;User ID=xx;Password=**;
　　　　　　pooling=true;max pool size=200" providerName="System.Data.SqlClient"/>
</connectionStrings>

DbHelper类

public class DBHelper
    {
        private static string connectionString = ConfigurationManager.ConnectionStrings["dh_web"].ConnectionString;
      
        //不带参数的执行命令
        public static int ExecuteCommand(string safeSql)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();
                SqlCommand cmd = new SqlCommand(safeSql, connection);
                return cmd.ExecuteNonQuery(); } } //带参数的执行命令 public static int ExecuteCommand(string sql, params SqlParameter[] values) { using (SqlConnection connection = new SqlConnection(connectionString)) { connection.Open(); SqlCommand cmd = new SqlCommand(sql, connection); cmd.Parameters.AddRange(values); return cmd.ExecuteNonQuery(); } } public static int GetScalar(string safeSql) { using (SqlConnection connection = new SqlConnection(connectionString)) { connection.Open(); SqlCommand cmd = new SqlCommand(safeSql, connection); return Convert.ToInt32(cmd.ExecuteScalar()); } } public static int GetScalar(string sql, params SqlParameter[] values) { using (SqlConnection connection = new SqlConnection(connectionString)) { connection.Open(); SqlCommand cmd = new SqlCommand(sql, connection); cmd.Parameters.AddRange(values); return Convert.ToInt32(cmd.ExecuteScalar()); } } public static SqlDataReader GetReader(string safeSql) { SqlConnection connection = new SqlConnection(connectionString); connection.Open(); SqlCommand cmd = new SqlCommand(safeSql, connection); return cmd.ExecuteReader(CommandBehavior.CloseConnection); } public static SqlDataReader GetReader(string sql, params SqlParameter[] values) { SqlConnection connection = new SqlConnection(connectionString); connection.Open(); SqlCommand cmd = new SqlCommand(sql, connection); cmd.Parameters.AddRange(values); return cmd.ExecuteReader(CommandBehavior.CloseConnection); } public static DataTable GetDataSet(string safeSql) { using (SqlConnection connection = new SqlConnection(connectionString)) { DataSet ds = new DataSet(); SqlCommand cmd = new SqlCommand(safeSql, connection); SqlDataAdapter da = new SqlDataAdapter(cmd); da.Fill(ds); return ds.Tables[0]; } } public static DataTable GetDataSet(string sql, params SqlParameter[] values) { using (SqlConnection connection = new SqlConnection(connectionString)) { DataSet ds = new DataSet(); SqlCommand cmd = new SqlCommand(sql, connection); cmd.Parameters.AddRange(values); SqlDataAdapter da = new SqlDataAdapter(cmd); da.Fill(ds); return ds.Tables[0]; } } }

注意：
CommandBehavior.CloseConnection解决了流读取数据模式下,数据库连接不能有效关闭的情况.
当某个XXXDataReader对象在生成时使用了CommandBehavior.CloseConnection,那数据库连接将在XXXDataReader对象关闭时自动关闭.