SQLite数据库操作类



配置addkey="SQLString"value="~\demo.db"/ . /* ************************************* *作用：SQLLiteServer操作实现 *作者：Monkey *日期:2011-10-27 *网址：www.redglove.net ************************************* */ using System; using System.Col

配置 .

/**************************************
* 作用：SQLLite Server操作实现
* 作者：Monkey
* 日期: 2011-10-27
* 网址：www.redglove.net
**************************************/

using System;
using System.Collections;
using System.Collections.Specialized;
using System.Data;
using System.Data.SQLite;//这个可以去网上下载
using System.Configuration;

public class SQLiteHelper
{
//数据库连接字符串(web.config来配置)，可以动态更改SQLString支持多数据库.
public static string connectionString = "Data Source=" + System.Web.HttpContext.Current.Server.MapPath(ConfigurationManager.AppSettings["SQLString"]);

public SQLiteHelper() { }

#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 执行简单SQL语句

///

/// 执行SQL语句，返回影响的记录数
///

/// SQL语句
/// 影响的记录数
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);
}
}
}
}

///

/// 执行SQL语句，设置命令的执行等待时间
///

///
///
///
public static int ExecuteSqlByTime(string SQLString, int Times)
{
using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
using (SQLiteCommand cmd = new SQLiteCommand(SQLString, connection))
{
try
{
connection.Open();
cmd.CommandTimeout = Times;
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (System.Data.SQLite.SQLiteException E)
{
connection.Close();
throw new Exception(E.Message);
}
}
}
}

///

/// 执行多条SQL语句，实现数据库事务。
///

/// 多条SQL语句
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);
}
}
}

///

/// 执行带一个存储过程参数的的SQL语句。
///

/// SQL语句
/// 参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加
/// 影响的记录数
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();
}
}
}

///

/// 执行带一个存储过程参数的的SQL语句。
///

/// SQL语句
/// 参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加
/// 影响的记录数
public static object ExecuteSqlGet(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();
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)
{
throw new Exception(E.Message);
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}

///

/// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例)
///

/// SQL语句
/// 图像字节,数据库的字段类型为image的情况
/// 影响的记录数
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();
}
}
}

///

/// 执行一条计算查询结果语句，返回查询结果（object）。
///

/// 计算查询结果语句
/// 查询结果（object）
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);
}
}
}
}

///

/// 执行查询语句，返回SQLiteDataReader(使用该方法切记要手工关闭SQLiteDataReader和连接)
///

/// 查询语句
/// SQLiteDataReader
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);
}
//finally //不能在此关闭，否则，返回的对象将无法使用
//{
// cmd.Dispose();
// connection.Close();
//}
}

///

/// 执行查询语句，返回DataSet
///

/// 查询语句
/// DataSet
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;
}
}

public static DataSet Query(string SQLString, string TableName)
{
using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
DataSet ds = new DataSet();
try
{
connection.Open();
SQLiteDataAdapter command = new SQLiteDataAdapter(SQLString, connection);
command.Fill(ds, TableName);
}
catch (System.Data.SQLite.SQLiteException ex)
{
throw new Exception(ex.Message);
}
return ds;
}
}

///

/// 执行查询语句，返回DataSet,设置命令的执行等待时间
///

///
///
///
public static DataSet Query(string SQLString, int Times)
{
using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
DataSet ds = new DataSet();
try
{
connection.Open();
SQLiteDataAdapter command = new SQLiteDataAdapter(SQLString, connection);
command.SelectCommand.CommandTimeout = Times;
command.Fill(ds, "ds");
}
catch (System.Data.SQLite.SQLiteException ex)
{
throw new Exception(ex.Message);
}
return ds;
}
}

#endregion

#region 执行带参数的SQL语句

///

/// 执行SQL语句，返回影响的记录数
///

/// SQL语句
/// 影响的记录数
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);
}
}
}
}

///

/// 执行多条SQL语句，实现数据库事务。
///

/// SQL语句的哈希表（key为sql语句，value是该语句的SQLiteParameter[]）
public static void ExecuteSqlTran(Hashtable SQLStringList)
{
using (SQLiteConnection conn = new SQLiteConnection(connectionString))
{
conn.Open();
using (SQLiteTransaction trans = conn.BeginTransaction())
{
SQLiteCommand cmd = new SQLiteCommand();
try
{
//循环
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;
}
}
}
}

///

/// 执行一条计算查询结果语句，返回查询结果（object）。
///

/// 计算查询结果语句
/// 查询结果（object）
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);
}
}
}
}

///

/// 执行查询语句，返回SQLiteDataReader (使用该方法切记要手工关闭SQLiteDataReader和连接)
///

/// 查询语句
/// SQLiteDataReader
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);
}
//finally //不能在此关闭，否则，返回的对象将无法使用
//{
// cmd.Dispose();
// connection.Close();