（转）c# 操作sqlite 数据库的类

原文地址：http://www.cnblogs.com/Leo_wl/archive/2010/06/23/1763735.html

using System;
using System.Text;
using System.Data;
using System.Data.SQLite;

namespace WQ.SQLite.DataBase
{

 
    public class SQLiteDataBase : IDisposable
    {
        SQLiteConnection conn;
        private int iTimeOut = 30;
        private string strErro;
        private string connStr;

        public SQLiteDataBase(string _connString)
        {
            connStr = _connString;
        }

        private SQLiteCommand CreateCommand(string sqlString)
        {
            this.Open(connString);
            SQLiteCommand command = new SQLiteCommand(sqlString, this.conn);
            command.CommandTimeout = this.TimeOut;
            command.CommandType = CommandType.Text;
            command.CommandText = sqlString;
            return command;
        }

        public bool ExcQuery(string sqlString)
        {
            try
            {
                SQLiteCommand command = new SQLiteCommand(sqlString, new SQLiteConnection(connString));
                command.Connection.Open();
                command.ExecuteNonQuery();
                command.Connection.Close();
                return true;
            }
            catch (Exception exception)
            {
                this.strErro = exception.ToString();
                return false;
            }
        }

        public DataTable GetDataTable(string sqlString)
        {
            try
            {
                SQLiteConnection selectConnection = new SQLiteConnection(connString);
                SQLiteDataAdapter adapter = new SQLiteDataAdapter(sqlString, selectConnection);
                DataSet dataSet = new DataSet();
                adapter.Fill(dataSet, "myTable");
                return dataSet.Tables["myTable"];
            }
            catch (Exception exception)
            {
                this.strErro = sqlString + "\n" + exception.Message;
                return null;
            }
        }

        public bool GetDataTable(string sqlString, ref DataTable DataTable)
        {
            try
            {
                SQLiteConnection selectConnection = new SQLiteConnection(connString);
                SQLiteDataAdapter adapter = new SQLiteDataAdapter(sqlString, selectConnection);
                DataSet dataSet = new DataSet();
                adapter.Fill(dataSet, "myTable");
                DataTable = dataSet.Tables["myTable"];
                return true;
            }
            catch (Exception exception)
            {
                this.strErro = sqlString + "\n" + exception.Message;
                return false;
            }
        }

        public bool GetDataTable(string sqlString, SQLiteParameter[] pa, ref DataTable dt)
        {
            try
            {
                SQLiteConnection selectConnection = new SQLiteConnection(connString);
                SQLiteDataAdapter adapter = new SQLiteDataAdapter(sqlString, selectConnection);
                DataSet dataSet = new DataSet();
                for (int i = 0; i < pa.Length; i++)
                {
                    adapter.SelectCommand.Parameters.Add(pa[i]);
                }
                adapter.Fill(dataSet, "myTable");
                dt = dataSet.Tables["myTable"];
                return true;
            }
            catch (Exception exception)
            {
                this.strErro = sqlString + "\n" + exception.Message;
                return false;
            }
        }

        public bool GetDataTable(string sqlString, int pageIndex, int maxRecords, ref DataTable DataTable)
        {
            try
            {
                SQLiteConnection selectConnection = new SQLiteConnection(connString);
                SQLiteDataAdapter adapter = new SQLiteDataAdapter(sqlString, selectConnection);
                DataSet dataSet = new DataSet();
                adapter.Fill(dataSet, pageIndex, maxRecords, "myTable");
                DataTable = dataSet.Tables["myTable"];
                return true;
            }
            catch (Exception exception)
            {
                this.strErro = sqlString + "\n" + exception.Message;
                return false;
            }
        }

        public string GetOneValue(string sqlString, SQLiteParameter[] pa)
        {
            SQLiteCommand command = new SQLiteCommand(sqlString, new SQLiteConnection(connString));
            for (int i = 0; i < pa.Length; i++)
            {
                command.Parameters.Add(pa[i]);
            }
            command.Connection.Open();
            string str = command.ExecuteScalar().ToString();
            command.Connection.Close();
            return str;
        }

        public string GetOneValue(string connString, string sqlString)
        {
            SQLiteCommand command = this.CreateCommand(sqlString);
            string str = command.ExecuteScalar().ToString();
            command.Connection.Close();
            return str;
        }

        private void Open(string _connectionString)
        {
            if (this.conn == null)
            {
                this.conn = new SQLiteConnection(_connectionString);
                this.conn.Open();
            }
            else if (this.conn.State != ConnectionState.Open)
            {
                this.conn.Open();
            }
        }

        public void Close()
        {
            if (this.conn != null)
            {
                this.conn.Close();
            }
            else if (this.conn.State == ConnectionState.Open)
            {
                this.conn.Close();
            }
        }

        public void Dispose()
        {
            if (this.conn != null)
            {
                this.conn.Dispose();
                this.conn = null;
            }
        }

        public string ErrString
        {
            get
            {
                return this.strErro;
            }
        }

        private string connString
        {
            get
            {
                return this.connStr;
            }
            set
            {
                this.connStr = value;
            }
        }

        public int TimeOut
        {
            get
            {
                return this.iTimeOut;
            }
            set
            {
                this.iTimeOut = value;
            }
        }

    }
}