用于sqlite数据库的SqlLiteHelper.cs 的类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.Data;
using System.Data.SQLite;
using System.Data.Common;

namespace JonseTest
{
   public abstract class SqlLiteHelper
    {
       public static string ConnSqlLiteDbPath = string.Empty;
       public static string ConnString
       {
           get
           {
               return string.Format(@"Data Source={0}",ConnSqlLiteDbPath);
           }
       }

       // 取datatable
       public static DataTable GetDataTable(out string sError,string sSQL)
       {
           DataTable dt = null;
           sError = string.Empty;

           try
           {
               SQLiteConnection conn = new SQLiteConnection(ConnString);
               conn.Open();
               SQLiteCommand cmd = new SQLiteCommand();
               cmd.CommandText = sSQL;
               cmd.Connection = conn;
               SQLiteDataAdapter dao = new SQLiteDataAdapter(cmd);
               dt = new DataTable();
               dao.Fill(dt);
           }
           catch (Exception ex)
           {
               sError = ex.Message;
           }

           return dt;
       }

       // 取dataset
       public static DataSet GetDataSet(out string sError,string sSQL)
       {
           DataSet ds = null;
           sError = string.Empty;

           try
           {
               SQLiteConnection conn = new SQLiteConnection(ConnString);
               conn.Open();
               SQLiteCommand cmd = new SQLiteCommand();
               cmd.CommandText = sSQL;
               cmd.Connection = conn;
               SQLiteDataAdapter dao = new SQLiteDataAdapter(cmd);
               ds = new DataSet();
               dao.Fill(ds);
           }
           catch (Exception ex)
           {
               sError = ex.Message;
           }

           return ds;
       }

       // 取某个单一的元素
       public static object GetSingle(out string sError,string sSQL)
       {
           DataTable dt = GetDataTable(out sError,sSQL);
           if (dt != null && dt.Rows.Count > 0)
           {
               return dt.Rows[0][0];
           }

           return null;
       }

       // 取最大的ID
       public static Int32 GetMaxID(out string sError,string sKeyField,string sTableName)
       {
           DataTable dt = GetDataTable(out sError,"select ifnull(max([" + sKeyField + "]),0) as MaxID from [" + sTableName + "]");
           if (dt != null && dt.Rows.Count > 0)
           {
               return Convert.ToInt32(dt.Rows[0][0].ToString());
           }

           return 0;
       }

       // 执行 insert,update,delete 动作，也可以使用事务
       public static bool UpdateData(out string sError,string sSQL,bool bUseTransaction=false)
       {
           int iResult = 0;
           sError = string.Empty;

           if (!bUseTransaction)
           {
               try
               {
                   SQLiteConnection conn = new SQLiteConnection(ConnString);
                   conn.Open();
                   SQLiteCommand comm = new SQLiteCommand(conn);
                   comm.CommandText = sSQL;
                   iResult = comm.ExecuteNonQuery();
               }
               catch (Exception ex)
               {
                   sError = ex.Message;
                   iResult = -1;
               }
           }
           else // 使用事务
           {
               DbTransaction trans =null;
               try
               {
                   SQLiteConnection conn = new SQLiteConnection(ConnString);
                   conn.Open();
                   trans = conn.BeginTransaction();
                   SQLiteCommand comm = new SQLiteCommand(conn);
                   comm.CommandText = sSQL;
                   iResult = comm.ExecuteNonQuery();
                   trans.Commit();
               }
               catch (Exception ex)
               {
                   sError = ex.Message;
                   iResult = -1;
                   trans.Rollback();
               }
           }

           return iResult >0;
       }

    }
}

 

关于具体如何调用 SqlLiteHelper ，请参考我的博文：

C# 使用sqlite 轻量级数据库

网址： http://www.52php.cn/article/p-pocobmnt-eq.html

希望对大家有所帮助。

（编辑：李大同）

【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!