C#封裝的Sqlite訪問類

mb78 9年前發布 | 3K 次閱讀 C# SQLite
C#封裝的Sqlite訪問類，要訪問Sqlite這下簡單了，直接調用此類中的方法即可
using System;
using System.Collections;
using System.Collections.Specialized;
using System.Data;
using System.Configuration;
using System.Data.SQLite;
namespace DAL
{
    internal abstract class DbHelperSQLite
    {

        public static string connectionString = "Data Source=" + AppDomain.CurrentDomain.BaseDirectory + @"dataleaf.db;Version=3;";
        public DbHelperSQLite()
        {
        }

    #region 公用方法

    public static int GetMaxID(string FieldName, string TableName)
    {
        string strsql = "select max(" + FieldName + ")+1 from " + TableName;
        object obj = GetSingle(strsql);
        if (obj == null)
        {
            return 1;
        }
        else
        {
            return int.Parse(obj.ToString());
        }
    }
    public static bool Exists(string strSql)
    {
        object obj = GetSingle(strSql);
        int cmdresult;
        if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
        {
            cmdresult = 0;
        }
        else
        {
            cmdresult = int.Parse(obj.ToString());
        }
        if (cmdresult == 0)
        {
            return false;
        }
        else
        {
            return true;
        }
    }
    public static bool Exists(string strSql, params SQLiteParameter[] cmdParms)
    {
        object obj = GetSingle(strSql, cmdParms);
        int cmdresult;
        if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
        {
            cmdresult = 0;
        }
        else
        {
            cmdresult = int.Parse(obj.ToString());
        }
        if (cmdresult == 0)
        {
            return false;
        }
        else
        {
            return true;
        }
    }

    #endregion

    #region  執行簡單SQL語句

    /// <summary>
    /// 執行SQL語句，返回影響的記錄數
    /// </summary>
    /// <param name="SQLString">SQL語句</param>
    /// <returns>影響的記錄數</returns>
    public static int ExecuteSql(string SQLString)
    {
        using (SQLiteConnection connection = new SQLiteConnection(connectionString))
        {
            using (SQLiteCommand cmd = new SQLiteCommand(SQLString, connection))
            {
                try
                {
                    connection.Open();
                    int rows = cmd.ExecuteNonQuery();
                    return rows;
                }
                catch (System.Data.SQLite.SQLiteException E)
                {
                    connection.Close();
                    throw new Exception(E.Message);
                }
            }
        }
    }

    /// <summary>
    /// 執行多條SQL語句，實現數據庫事務。
    /// </summary>
    /// <param name="SQLStringList">多條SQL語句</param>    
    public static void ExecuteSqlTran(ArrayList SQLStringList)
    {
        using (SQLiteConnection conn = new SQLiteConnection(connectionString))
        {
            conn.Open();
            SQLiteCommand cmd = new SQLiteCommand();
            cmd.Connection = conn;
            SQLiteTransaction tx = conn.BeginTransaction();
            cmd.Transaction = tx;
            try
            {
                for (int n = 0; n < SQLStringList.Count; n++)
                {
                    string strsql = SQLStringList[n].ToString();
                    if (strsql.Trim().Length > 1)
                    {
                        cmd.CommandText = strsql;
                        cmd.ExecuteNonQuery();
                    }
                }
                tx.Commit();
            }
            catch (System.Data.SQLite.SQLiteException E)
            {
                tx.Rollback();
                throw new Exception(E.Message);
            }
        }
    }
    /// <summary>
    /// 執行帶一個存儲過程參數的的SQL語句。
    /// </summary>
    /// <param name="SQLString">SQL語句</param>
    /// <param name="content">參數內容,比如一個字段是格式復雜的文章，有特殊符號，可以通過這個方式添加</param>
    /// <returns>影響的記錄數</returns>
    public static int ExecuteSql(string SQLString, string content)
    {
        using (SQLiteConnection connection = new SQLiteConnection(connectionString))
        {
            SQLiteCommand cmd = new SQLiteCommand(SQLString, connection);
            SQLiteParameter myParameter = new SQLiteParameter("@content", DbType.String);
            myParameter.Value = content;
            cmd.Parameters.Add(myParameter);
            try
            {
                connection.Open();
                int rows = cmd.ExecuteNonQuery();
                return rows;
            }
            catch (System.Data.SQLite.SQLiteException E)
            {
                throw new Exception(E.Message);
            }
            finally
            {
                cmd.Dispose();
                connection.Close();
            }
        }
    }
    /// <summary>
    /// 向數據庫里插入圖像格式的字段(和上面情況類似的另一種實例)
    /// </summary>
    /// <param name="strSQL">SQL語句</param>
    /// <param name="fs">圖像字節,數據庫的字段類型為image的情況</param>
    /// <returns>影響的記錄數</returns>
    public static int ExecuteSqlInsertImg(string strSQL, byte[] fs)
    {
        using (SQLiteConnection connection = new SQLiteConnection(connectionString))
        {
            SQLiteCommand cmd = new SQLiteCommand(strSQL, connection);
            SQLiteParameter myParameter = new SQLiteParameter("@fs", DbType.Binary);
            myParameter.Value = fs;
            cmd.Parameters.Add(myParameter);
            try
            {
                connection.Open();
                int rows = cmd.ExecuteNonQuery();
                return rows;
            }
            catch (System.Data.SQLite.SQLiteException E)
            {
                throw new Exception(E.Message);
            }
            finally
            {
                cmd.Dispose();
                connection.Close();
            }
        }
    }

    /// <summary>
    /// 執行一條計算查詢結果語句，返回查詢結果（object）。
    /// </summary>
    /// <param name="SQLString">計算查詢結果語句</param>
    /// <returns>查詢結果（object）</returns>
    public static object GetSingle(string SQLString)
    {
        using (SQLiteConnection connection = new SQLiteConnection(connectionString))
        {
            using (SQLiteCommand cmd = new SQLiteCommand(SQLString, connection))
            {
                try
                {
                    connection.Open();
                    object obj = cmd.ExecuteScalar();
                    if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
                    {
                        return null;
                    }
                    else
                    {
                        return obj;
                    }
                }
                catch (System.Data.SQLite.SQLiteException e)
                {
                    connection.Close();
                    throw new Exception(e.Message);
                }
            }
        }
    }
    /// <summary>
    /// 執行查詢語句，返回SQLiteDataReader
    /// </summary>
    /// <param name="strSQL">查詢語句</param>
    /// <returns>SQLiteDataReader</returns>
    public static SQLiteDataReader ExecuteReader(string strSQL)
    {
        SQLiteConnection connection = new SQLiteConnection(connectionString);
        SQLiteCommand cmd = new SQLiteCommand(strSQL, connection);
        try
        {
            connection.Open();
            SQLiteDataReader myReader = cmd.ExecuteReader();
            return myReader;
        }
        catch (System.Data.SQLite.SQLiteException e)
        {
            throw new Exception(e.Message);
        }

    }
    /// <summary>
    /// 執行查詢語句，返回DataSet
    /// </summary>
    /// <param name="SQLString">查詢語句</param>
    /// <returns>DataSet</returns>
    public static DataSet Query(string SQLString)
    {
        using (SQLiteConnection connection = new SQLiteConnection(connectionString))
        {
            DataSet ds = new DataSet();
            try
            {
                connection.Open();
                SQLiteDataAdapter command = new SQLiteDataAdapter(SQLString, connection);
                command.Fill(ds, "ds");
            }
            catch (System.Data.SQLite.SQLiteException ex)
            {
                throw new Exception(ex.Message);
            }
            return ds;
        }
    }


    #endregion

    #region 執行帶參數的SQL語句

    /// <summary>
    /// 執行SQL語句，返回影響的記錄數
    /// </summary>
    /// <param name="SQLString">SQL語句</param>
    /// <returns>影響的記錄數</returns>
    public static int ExecuteSql(string SQLString, params SQLiteParameter[] cmdParms)
    {
        using (SQLiteConnection connection = new SQLiteConnection(connectionString))
        {
            using (SQLiteCommand cmd = new SQLiteCommand())
            {
                try
                {
                    PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                    int rows = cmd.ExecuteNonQuery();
                    cmd.Parameters.Clear();
                    return rows;
                }
                catch (System.Data.SQLite.SQLiteException E)
                {
                    throw new Exception(E.Message);
                }
            }
        }
    }


    /// <summary>
    /// 執行多條SQL語句，實現數據庫事務。
    /// </summary>
    /// <param name="SQLStringList">SQL語句的哈希表（key為sql語句，value是該語句的SQLiteParameter[]）</param>
    public static void ExecuteSqlTran(Hashtable SQLStringList)
    {
        using (SQLiteConnection conn = new SQLiteConnection(connectionString))
        {
            conn.Open();
            using (SQLiteTransaction trans = conn.BeginTransaction())
            {
                SQLiteCommand cmd = new SQLiteCommand();
                try
                {
                    //循環
                    foreach (DictionaryEntry myDE in SQLStringList)
                    {
                        string cmdText = myDE.Key.ToString();
                        SQLiteParameter[] cmdParms = (SQLiteParameter[])myDE.Value;
                        PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
                        int val = cmd.ExecuteNonQuery();
                        cmd.Parameters.Clear();

                        trans.Commit();
                    }
                }
                catch
                {
                    trans.Rollback();
                    throw;
                }
            }
        }
    }


    /// <summary>
    /// 執行一條計算查詢結果語句，返回查詢結果（object）。
    /// </summary>
    /// <param name="SQLString">計算查詢結果語句</param>
    /// <returns>查詢結果（object）</returns>
    public static object GetSingle(string SQLString, params SQLiteParameter[] cmdParms)
    {
        using (SQLiteConnection connection = new SQLiteConnection(connectionString))
        {
            using (SQLiteCommand cmd = new SQLiteCommand())
            {
                try
                {
                    PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                    object obj = cmd.ExecuteScalar();
                    cmd.Parameters.Clear();
                    if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
                    {
                        return null;
                    }
                    else
                    {
                        return obj;
                    }
                }
                catch (System.Data.SQLite.SQLiteException e)
                {
                    throw new Exception(e.Message);
                }
            }
        }
    }

    /// <summary>
    /// 執行查詢語句，返回SQLiteDataReader
    /// </summary>
    /// <param name="strSQL">查詢語句</param>
    /// <returns>SQLiteDataReader</returns>
    public static SQLiteDataReader ExecuteReader(string SQLString, params SQLiteParameter[] cmdParms)
    {
        SQLiteConnection connection = new SQLiteConnection(connectionString);
        SQLiteCommand cmd = new SQLiteCommand();
        try
        {
            PrepareCommand(cmd, connection, null, SQLString, cmdParms);
            SQLiteDataReader myReader = cmd.ExecuteReader();
            cmd.Parameters.Clear();
            return myReader;
        }
        catch (System.Data.SQLite.SQLiteException e)
        {
            throw new Exception(e.Message);
        }

    }

    /// <summary>
    /// 執行查詢語句，返回DataSet
    /// </summary>
    /// <param name="SQLString">查詢語句</param>
    /// <returns>DataSet</returns>
    public static DataSet Query(string SQLString, params SQLiteParameter[] cmdParms)
    {
        using (SQLiteConnection connection = new SQLiteConnection(connectionString))
        {
            SQLiteCommand cmd = new SQLiteCommand();
            PrepareCommand(cmd, connection, null, SQLString, cmdParms);
            using (SQLiteDataAdapter da = new SQLiteDataAdapter(cmd))
            {
                DataSet ds = new DataSet();
                try
                {
                    da.Fill(ds, "ds");
                    cmd.Parameters.Clear();
                }
                catch (System.Data.SQLite.SQLiteException ex)
                {
                    throw new Exception(ex.Message);
                }
                return ds;
            }
        }
    }


    private static void PrepareCommand(SQLiteCommand cmd, SQLiteConnection conn, SQLiteTransaction trans, string cmdText, SQLiteParameter[] cmdParms)
    {
        if (conn.State != ConnectionState.Open)
            conn.Open();
        cmd.Connection = conn;
        cmd.CommandText = cmdText;
        if (trans != null)
            cmd.Transaction = trans;
        cmd.CommandType = CommandType.Text;//cmdType;
        if (cmdParms != null)
        {
            foreach (SQLiteParameter parm in cmdParms)
                cmd.Parameters.Add(parm);
        }
    }

    #endregion
}

}</pre>
本文由用戶 mb78 自行上傳分享，僅供網友學習交流。所有權歸原作者，若您的權利被侵害，請聯系管理員。
轉載本站原創文章，請注明出處，并保留原始鏈接、圖片水印。
本站是一個以用戶分享為主的開源技術平臺，歡迎各類分享！
本文地址：http://www.baiduhome.net/code/view/1430553790177
C# SQLite
C#封裝的Sqlite訪問類

相關代碼

相關文檔

相關經驗

目錄
