DBHelper:
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Data.SqlClient; using System.Data.Sql; using System.Data; namespace DAL { public class DBhelper { private static string Constr = "server=.;database=PaiPaiDB;uid=sa;pwd=123"; private static SqlConnection conn; private static SqlDataAdapter da; private static SqlCommand cmd; private static DBhelper dbhelper; public DBhelper() { conn = new SqlConnection(Constr); } public static DBhelper Instance() { if (dbhelper == null) { dbhelper = new DBhelper(); } return dbhelper; } void DBOpen() { if (conn.State == ConnectionState.Closed) { conn.Open(); } } void DBClose() { if (conn.State == ConnectionState.Open) { conn.Close(); } } public DataTable GetDtatTableBySql(string sql) { DBOpen(); DataTable dt = new DataTable(); da = new SqlDataAdapter(sql, conn); try { da.Fill(dt); return dt; } catch (Exception) { return null; } finally { DBClose(); } } public bool ExcuteSql(string sql) { DBOpen(); cmd = new SqlCommand(sql, conn); try { cmd.ExecuteNonQuery(); return true; } catch (Exception) { return false; } finally { DBClose(); } } public bool ExcuteProcedure(string proName, SqlParameter[] paras) { DBOpen(); cmd = new SqlCommand(proName, conn); cmd.CommandType = CommandType.StoredProcedure; for (int i = 0; i < paras.Length; i++) { cmd.Parameters.Add(paras[i]); } try { cmd.ExecuteNonQuery(); return true; } catch (Exception) { return false; } finally { DBClose(); } } } }
调用方法:
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Data; namespace DAL { public class GoodsService { //查询 public static DataTable GetDtatTableBySql(string sql) { DataTable dt = DBhelper.Instance().GetDtatTableBySql(sql); if (dt != null && dt.Rows.Count > 0) { return dt; } else { return null; } } //增加 删除 修改 public static bool ExecuteSql(string sql) { bool a; a = DBhelper.Instance().ExcuteSql(sql); return a; } } }