C#封装的Sqlite访问类实例
本文实例讲述了C#封装的Sqlite访问类。分享给大家供大家参考。具体分析如下：
C#封装的Sqlite访问类，要访问Sqlite这下简单了，直接调用此类中的方法即可
usingSystem;
usingSystem.Collections;
usingSystem.Collections.Specialized;
usingSystem.Data;
usingSystem.Configuration;
usingSystem.Data.SQLite;
namespaceDAL
{
internalabstractclassDbHelperSQLite
{
publicstaticstringconnectionString="DataSource="+AppDomain.CurrentDomain.BaseDirectory+@"dataleaf.db;Version=3;";
publicDbHelperSQLite()
{
}
#region公用方法
publicstaticintGetMaxID(stringFieldName,stringTableName)
{
stringstrsql="selectmax("+FieldName+")+1from"+TableName;
objectobj=GetSingle(strsql);
if(obj==null)
{
return1;
}
else
{
returnint.Parse(obj.ToString());
}
}
publicstaticboolExists(stringstrSql)
{
objectobj=GetSingle(strSql);
intcmdresult;
if((Object.Equals(obj,null))||(Object.Equals(obj,System.DBNull.Value)))
{
cmdresult=0;
}
else
{
cmdresult=int.Parse(obj.ToString());
}
if(cmdresult==0)
{
returnfalse;
}
else
{
returntrue;
}
}
publicstaticboolExists(stringstrSql,paramsSQLiteParameter[]cmdParms)
{
objectobj=GetSingle(strSql,cmdParms);
intcmdresult;
if((Object.Equals(obj,null))||(Object.Equals(obj,System.DBNull.Value)))
{
cmdresult=0;
}
else
{
cmdresult=int.Parse(obj.ToString());
}
if(cmdresult==0)
{
returnfalse;
}
else
{
returntrue;
}
}
#endregion
#region执行简单SQL语句
///<summary>
///执行SQL语句，返回影响的记录数
///</summary>
///<paramname="SQLString">SQL语句</param>
///<returns>影响的记录数</returns>
publicstaticintExecuteSql(stringSQLString)
{
using(SQLiteConnectionconnection=newSQLiteConnection(connectionString))
{
using(SQLiteCommandcmd=newSQLiteCommand(SQLString,connection))
{
try
{
connection.Open();
introws=cmd.ExecuteNonQuery();
returnrows;
}
catch(System.Data.SQLite.SQLiteExceptionE)
{
connection.Close();
thrownewException(E.Message);
}
}
}
}
///<summary>
///执行多条SQL语句，实现数据库事务。
///</summary>
///<paramname="SQLStringList">多条SQL语句</param>
publicstaticvoidExecuteSqlTran(ArrayListSQLStringList)
{
using(SQLiteConnectionconn=newSQLiteConnection(connectionString))
{
conn.Open();
SQLiteCommandcmd=newSQLiteCommand();
cmd.Connection=conn;
SQLiteTransactiontx=conn.BeginTransaction();
cmd.Transaction=tx;
try
{
for(intn=0;n<SQLStringList.Count;n++)
{
stringstrsql=SQLStringList[n].ToString();
if(strsql.Trim().Length>1)
{
cmd.CommandText=strsql;
cmd.ExecuteNonQuery();
}
}
tx.Commit();
}
catch(System.Data.SQLite.SQLiteExceptionE)
{
tx.Rollback();
thrownewException(E.Message);
}
}
}
///<summary>
///执行带一个存储过程参数的的SQL语句。
///</summary>
///<paramname="SQLString">SQL语句</param>
///<paramname="content">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</param>
///<returns>影响的记录数</returns>
publicstaticintExecuteSql(stringSQLString,stringcontent)
{
using(SQLiteConnectionconnection=newSQLiteConnection(connectionString))
{
SQLiteCommandcmd=newSQLiteCommand(SQLString,connection);
SQLiteParametermyParameter=newSQLiteParameter("@content",DbType.String);
myParameter.Value=content;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
introws=cmd.ExecuteNonQuery();
returnrows;
}
catch(System.Data.SQLite.SQLiteExceptionE)
{
thrownewException(E.Message);
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
///<summary>
///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)
///</summary>
///<paramname="strSQL">SQL语句</param>
///<paramname="fs">图像字节,数据库的字段类型为image的情况</param>
///<returns>影响的记录数</returns>
publicstaticintExecuteSqlInsertImg(stringstrSQL,byte[]fs)
{
using(SQLiteConnectionconnection=newSQLiteConnection(connectionString))
{
SQLiteCommandcmd=newSQLiteCommand(strSQL,connection);
SQLiteParametermyParameter=newSQLiteParameter("@fs",DbType.Binary);
myParameter.Value=fs;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
introws=cmd.ExecuteNonQuery();
returnrows;
}
catch(System.Data.SQLite.SQLiteExceptionE)
{
thrownewException(E.Message);
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
///<summary>
///执行一条计算查询结果语句，返回查询结果（object）。
///</summary>
///<paramname="SQLString">计算查询结果语句</param>
///<returns>查询结果（object）</returns>
publicstaticobjectGetSingle(stringSQLString)
{
using(SQLiteConnectionconnection=newSQLiteConnection(connectionString))
{
using(SQLiteCommandcmd=newSQLiteCommand(SQLString,connection))
{
try
{
connection.Open();
objectobj=cmd.ExecuteScalar();
if((Object.Equals(obj,null))||(Object.Equals(obj,System.DBNull.Value)))
{
returnnull;
}
else
{
returnobj;
}
}
catch(System.Data.SQLite.SQLiteExceptione)
{
connection.Close();
thrownewException(e.Message);
}
}
}
}
///<summary>
///执行查询语句，返回SQLiteDataReader
///</summary>
///<paramname="strSQL">查询语句</param>
///<returns>SQLiteDataReader</returns>
publicstaticSQLiteDataReaderExecuteReader(stringstrSQL)
{
SQLiteConnectionconnection=newSQLiteConnection(connectionString);
SQLiteCommandcmd=newSQLiteCommand(strSQL,connection);
try
{
connection.Open();
SQLiteDataReadermyReader=cmd.ExecuteReader();
returnmyReader;
}
catch(System.Data.SQLite.SQLiteExceptione)
{
thrownewException(e.Message);
}
}
///<summary>
///执行查询语句，返回DataSet
///</summary>
///<paramname="SQLString">查询语句</param>
///<returns>DataSet</returns>
publicstaticDataSetQuery(stringSQLString)
{
using(SQLiteConnectionconnection=newSQLiteConnection(connectionString))
{
DataSetds=newDataSet();
try
{
connection.Open();
SQLiteDataAdaptercommand=newSQLiteDataAdapter(SQLString,connection);
command.Fill(ds,"ds");
}
catch(System.Data.SQLite.SQLiteExceptionex)
{
thrownewException(ex.Message);
}
returnds;
}
}
#endregion
#region执行带参数的SQL语句
///<summary>
///执行SQL语句，返回影响的记录数
///</summary>
///<paramname="SQLString">SQL语句</param>
///<returns>影响的记录数</returns>
publicstaticintExecuteSql(stringSQLString,paramsSQLiteParameter[]cmdParms)
{
using(SQLiteConnectionconnection=newSQLiteConnection(connectionString))
{
using(SQLiteCommandcmd=newSQLiteCommand())
{
try
{
PrepareCommand(cmd,connection,null,SQLString,cmdParms);
introws=cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
returnrows;
}
catch(System.Data.SQLite.SQLiteExceptionE)
{
thrownewException(E.Message);
}
}
}
}
///<summary>
///执行多条SQL语句，实现数据库事务。
///</summary>
///<paramname="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的SQLiteParameter[]）</param>
publicstaticvoidExecuteSqlTran(HashtableSQLStringList)
{
using(SQLiteConnectionconn=newSQLiteConnection(connectionString))
{
conn.Open();
using(SQLiteTransactiontrans=conn.BeginTransaction())
{
SQLiteCommandcmd=newSQLiteCommand();
try
{
//循环
foreach(DictionaryEntrymyDEinSQLStringList)
{
stringcmdText=myDE.Key.ToString();
SQLiteParameter[]cmdParms=(SQLiteParameter[])myDE.Value;
PrepareCommand(cmd,conn,trans,cmdText,cmdParms);
intval=cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
trans.Commit();
}
}
catch
{
trans.Rollback();
throw;
}
}
}
}
///<summary>
///执行一条计算查询结果语句，返回查询结果（object）。
///</summary>
///<paramname="SQLString">计算查询结果语句</param>
///<returns>查询结果（object）</returns>
publicstaticobjectGetSingle(stringSQLString,paramsSQLiteParameter[]cmdParms)
{
using(SQLiteConnectionconnection=newSQLiteConnection(connectionString))
{
using(SQLiteCommandcmd=newSQLiteCommand())
{
try
{
PrepareCommand(cmd,connection,null,SQLString,cmdParms);
objectobj=cmd.ExecuteScalar();
cmd.Parameters.Clear();
if((Object.Equals(obj,null))||(Object.Equals(obj,System.DBNull.Value)))
{
returnnull;
}
else
{
returnobj;
}
}
catch(System.Data.SQLite.SQLiteExceptione)
{
thrownewException(e.Message);
}
}
}
}
///<summary>
///执行查询语句，返回SQLiteDataReader
///</summary>
///<paramname="strSQL">查询语句</param>
///<returns>SQLiteDataReader</returns>
publicstaticSQLiteDataReaderExecuteReader(stringSQLString,paramsSQLiteParameter[]cmdParms)
{
SQLiteConnectionconnection=newSQLiteConnection(connectionString);
SQLiteCommandcmd=newSQLiteCommand();
try
{
PrepareCommand(cmd,connection,null,SQLString,cmdParms);
SQLiteDataReadermyReader=cmd.ExecuteReader();
cmd.Parameters.Clear();
returnmyReader;
}
catch(System.Data.SQLite.SQLiteExceptione)
{
thrownewException(e.Message);
}
}
///<summary>
///执行查询语句，返回DataSet
///</summary>
///<paramname="SQLString">查询语句</param>
///<returns>DataSet</returns>
publicstaticDataSetQuery(stringSQLString,paramsSQLiteParameter[]cmdParms)
{
using(SQLiteConnectionconnection=newSQLiteConnection(connectionString))
{
SQLiteCommandcmd=newSQLiteCommand();
PrepareCommand(cmd,connection,null,SQLString,cmdParms);
using(SQLiteDataAdapterda=newSQLiteDataAdapter(cmd))
{
DataSetds=newDataSet();
try
{
da.Fill(ds,"ds");
cmd.Parameters.Clear();
}
catch(System.Data.SQLite.SQLiteExceptionex)
{
thrownewException(ex.Message);
}
returnds;
}
}
}
privatestaticvoidPrepareCommand(SQLiteCommandcmd,SQLiteConnectionconn,SQLiteTransactiontrans,stringcmdText,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(SQLiteParameterparmincmdParms)
cmd.Parameters.Add(parm);
}
}
#endregion
}
}
希望本文所述对大家的C#程序设计有所帮助。