本文主要向大家介绍了Oracle数据库入门的Oracle帮助类，通过具体的代码向大家展示，希望对大家学习Oracle数据库入门有所帮助。

/// <summary>
    /// Copyright (C) Maticsoft
/// 数据访问基础类(基于Oracle)
/// 可以用户可以修改满足自己项目的需要。
/// </summary>
public abstract class DbHelperOra
{
        //数据库连接字符串(web.config来配置)，可以动态更改connectionString支持多数据库.  
        public static string connectionString = PubConstant.ConnectionString;     
public DbHelperOra()
{  
}
 
        #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 OracleParameter[] 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;
            }
        }
 
        public static int GetSequence(string SequenceName)
        {
            string strsql = "select " + SequenceName + ".nextval from dual";
            object obj = GetSingle(strsql);
            if (obj == null)
            {
                return 0;
            }
            else {
                return int.Parse(obj.ToString());
            }
        }
        #endregion
 
        public static string GetServerDateTime()
        {
            //string SQLString = "Select To_Char(SYSDATE，‘yyyyMMddHHmmss‘) from dual";
            string datetime = "";
            string SQLString = "select SYSDATE from dual";
            using (OracleConnection connection = new OracleConnection(connectionString))
            {
                using (OracleCommand cmd = new OracleCommand(SQLString, connection))
                {
                    try
                    {
                        connection.Open();
                        OracleDataReader dataReader = cmd.ExecuteReader();
                        if (dataReader.Read())
                        {
                            datetime = dataReader[0].ToString();
                        }
                        dataReader.Close();
                    }
                    catch (System.Data.OracleClient.OracleException E)
                    {
                        connection.Close();
                        throw new Exception(E.Message);
                    }
                }
            }
            return datetime;
        }
#region  执行简单SQL语句
 
/// <summary>
/// 执行SQL语句，返回影响的记录数
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSql(string SQLString)
{
using (OracleConnection connection = new OracleConnection(connectionString))
{    
using (OracleCommand cmd = new OracleCommand(SQLString,connection))
{
try
{  
connection.Open();
int rows=cmd.ExecuteNonQuery();
return rows;
}
catch(System.Data.OracleClient.OracleException E)
{    
connection.Close();
throw new Exception(E.Message);
}
}    
}
}
/// <summary>
/// 执行多条SQL语句，实现数据库事务。
/// </summary>
/// <param name="SQLStringList">多条SQL语句</param>  
public static bool ExecuteSqlTran(ArrayList SQLStringList)
{
using (OracleConnection conn = new OracleConnection(connectionString))
{
conn.Open();
OracleCommand cmd = new OracleCommand();
cmd.Connection=conn;    
OracleTransaction 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();
                    return true;
}
catch //(System.Data.OracleClient.OracleException E)
{  
tx.Rollback();
                    return false;
//throw new Exception(E.Message);
}
}
}
/// <summary>
/// 执行带一个存储过程参数的的SQL语句。
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <param name="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>
public static int ExecuteSql(string SQLString,string content)
{    
using (OracleConnection connection = new OracleConnection(connectionString))
{
OracleCommand cmd = new OracleCommand(SQLString,connection);
                System.Data.OracleClient.OracleParameter myParameter = new System.Data.OracleClient.OracleParameter("@content", OracleType.NVarChar);
myParameter.Value = content ;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
int rows=cmd.ExecuteNonQuery();
return rows;
}
catch(System.Data.OracleClient.OracleException E)
{    
throw new Exception(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>
/// <param name="strSQL">SQL语句</param>
/// <param name="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>
public static int ExecuteSqlInsertImg(string strSQL,byte[] fs)
{  
using (OracleConnection connection = new OracleConnection(connectionString))
{
OracleCommand cmd = new OracleCommand(strSQL,connection);
                System.Data.OracleClient.OracleParameter myParameter = new System.Data.OracleClient.OracleParameter("@fs", OracleType.LongRaw);
myParameter.Value = fs ;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
int rows=cmd.ExecuteNonQuery();
return rows;
}
catch(System.Data.OracleClient.OracleException E)
{    
throw new Exception(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>
/// <param name="SQLString">计算查询结果语句</param>
/// <returns>查询结果（object）</returns>
public static object GetSingle(string SQLString)
{
using (OracleConnection connection = new OracleConnection(connectionString))
{
using(OracleCommand cmd = new OracleCommand(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.OracleClient.OracleException e)
{      
connection.Close();
throw new Exception(e.Message);
}
}
}
}
/// <summary>
        /// 执行查询语句，返回OracleDataReader ( 注意：调用该方法后，一定要对SqlDataReader进行Close )
/// </summary>
/// <param name="strSQL">查询语句</param>
/// <returns>OracleDataReader</returns>
public static OracleDataReader ExecuteReader(string strSQL)
{
OracleConnection connection = new OracleConnection(connectionString);  
OracleCommand cmd = new OracleCommand(strSQL,connection);    
try
{
connection.Open();
                OracleDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
return myReader;
}
catch(System.Data.OracleClient.OracleException e)
{        
throw new Exception(e.Message);
}  
}  
/// <summary>
/// 执行查询语句，返回DataSet
/// </summary>
/// <param name="SQLString">查询语句</param>
/// <returns>DataSet</returns>
public static DataSet Query(string SQLString)
{
using (OracleConnection connection = new OracleConnection(connectionString))
{
DataSet ds = new DataSet();
try
{
connection.Open();
OracleDataAdapter command = new OracleDataAdapter(SQLString,connection);    
command.Fill(ds,"ds");
}
catch(System.Data.OracleClient.OracleException ex)
{    
throw new Exception(ex.Message);
}  
return ds;
}  
}
        
#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>
/// <param name="SQLString">SQL语句</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSql(string SQLString,params OracleParameter[] cmdParms)
{
using (OracleConnection connection = new OracleConnection(connectionString))
{    
using (OracleCommand cmd = new OracleCommand())
{
try
{  
PrepareCommand(cmd, connection, null,SQLString, cmdParms);
int rows=cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return rows;
}
catch(System.Data.OracleClient.OracleException E)
{    
throw new Exception(E.Message);
}
}    
}
}
        /// <summary>
        /// 执行多条SQL语句，实现数据库事务。
        /// </summary>
        /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的OracleParameter[]）</param>
        public static bool ExecuteSqlTran(System.Collections.Generic.List<Hashtable> SQLStringList)
        {
            using (OracleConnection conn = new OracleConnection(connectionString))
            {
                conn.Open();
                using (OracleTransaction trans = conn.BeginTransaction())
                {
                    OracleCommand cmd = new OracleCommand();
                    try
                    {
                        //循环
                        foreach (Hashtable item in SQLStringList)
                        {
                            foreach (DictionaryEntry myDE in item)
                            {
                                string cmdText = myDE.Key.ToString();
                                OracleParameter[] cmdParms = (OracleParameter[])myDE.Value;
                                PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
                                int val = cmd.ExecuteNonQuery();
                                cmd.Parameters.Clear();
                            }
                        }
                        trans.Commit();
                        return true;
                    }
                    catch
                    {
                        trans.Rollback();
                        //throw;
                        return false;
                    }
                    finally
                    {
                        conn.Close();
                        conn.Dispose();//打开后需要关闭释放
                    }
                }
            }
        }
 
        public static bool Manange(System.Collections.Hashtable hash)
        {
            bool b = false;
            foreach (System.Collections.DictionaryEntry entry in hash)
            {
                OracleParameter[] parameters = (OracleParameter[])entry.Value;
                int rows = ExecuteSql(entry.Key.ToString(), parameters);
                if (rows > 0)
                {
                    b = true;
                }
                else
                {
                    b = false;
                }
            }
            return b;
        }
/// <summary>
/// 执行多条SQL语句，实现数据库事务。
/// </summary>
/// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的OracleParameter[]）</param>
public static bool ExecuteSqlTran(Hashtable SQLStringList)
{  
using (OracleConnection conn = new OracleConnection(connectionString))
{
conn.Open();
using (OracleTransaction trans = conn.BeginTransaction())
{
OracleCommand cmd = new OracleCommand();
                    try
                    {
                        //循环
                        foreach (DictionaryEntry myDE in SQLStringList)
                        {
                            string cmdText = myDE.Key.ToString();
                            OracleParameter[] cmdParms = (OracleParameter[])myDE.Value;
                            PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
                            int val = cmd.ExecuteNonQuery();
                            cmd.Parameters.Clear();
 
 
                        }
                        trans.Commit();
                        return true;
                    }
                    catch
                    {
                        trans.Rollback();
                        //throw;
                        return false;
                    }
                    finally
                    {
                        conn.Close();
                        conn.Dispose();//打开后需要关闭释放
                    }
}    
}
}
/// <summary>
/// 执行一条计算查询结果语句，返回查询结果（object）。
/// </summary>
/// <param name="SQLString">计算查询结果语句</param>
/// <returns>查询结果（object）</returns>
public static object GetSingle(string SQLString,params OracleParameter[] cmdParms)
{
using (OracleConnection connection = new OracleConnection(connectionString))
{
using (OracleCommand cmd = new OracleCommand())
{
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.OracleClient.OracleException e)
{    
throw new Exception(e.Message);
}    
}
}
}
/// <summary>
        /// 执行查询语句，返回OracleDataReader ( 注意：调用该方法后，一定要对SqlDataReader进行Close )
/// </summary>
/// <param name="strSQL">查询语句</param>
/// <returns>OracleDataReader</returns>
public static OracleDataReader ExecuteReader(string SQLString,params OracleParameter[] cmdParms)
{  
OracleConnection connection = new OracleConnection(connectionString);
OracleCommand cmd = new OracleCommand();    
try
{
PrepareCommand(cmd, connection, null,SQLString, cmdParms);
                OracleDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
cmd.Parameters.Clear();
return myReader;
}
catch(System.Data.OracleClient.OracleException e)
{        
throw new Exception(e.Message);
}    
}  
/// <summary>
/// 执行查询语句，返回DataSet
/// </summary>
/// <param name="SQLString">查询语句</param>
/// <returns>DataSet</returns>
public static DataSet Query(string SQLString,params OracleParameter[] cmdParms)
{
using (OracleConnection connection = new OracleConnection(connectionString))
{
OracleCommand cmd = new OracleCommand();
PrepareCommand(cmd, connection, null,SQLString, cmdParms);
using( OracleDataAdapter da = new OracleDataAdapter(cmd) )
{
DataSet ds = new DataSet();
try
{            
da.Fill(ds,"ds");
cmd.Parameters.Clear();
}
catch(System.Data.OracleClient.OracleException ex)
{    
throw new Exception(ex.Message);
}  
return ds;
}    
}  
}
 
 
private static void PrepareCommand(OracleCommand cmd,OracleConnection conn,OracleTransaction trans, string cmdText, OracleParameter[] 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 (OracleParameter parm in cmdParms)
cmd.Parameters.Add(parm);
}
}
 
#endregion
 
#region 存储过程操作
 
/// <summary>
        /// 执行存储过程 返回SqlDataReader ( 注意：调用该方法后，一定要对SqlDataReader进行Close )
/// </summary>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <returns>OracleDataReader</returns>
public static OracleDataReader RunProcedure(string storedProcName, IDataParameter[] parameters )
{
OracleConnection connection = new OracleConnection(connectionString);
OracleDataReader returnReader;
connection.Open();
OracleCommand command = BuildQueryCommand( connection,storedProcName, parameters );
command.CommandType = CommandType.StoredProcedure;
            returnReader = command.ExecuteReader(CommandBehavior.CloseConnection);    
return returnReader;  
}
/// <summary>
/// 执行存储过程
/// </summary>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <param name="tableName">DataSet结果中的表名</param>
/// <returns>DataSet</returns>
public static DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, string tableName )
{
using (OracleConnection connection = new OracleConnection(connectionString))
{
DataSet dataSet = new DataSet();
connection.Open();
OracleDataAdapter sqlDA = new OracleDataAdapter();
sqlDA.SelectCommand = BuildQueryCommand(connection, storedProcName, parameters );
sqlDA.Fill( dataSet, tableName );
connection.Close();
return dataSet;
}
}
 
/// <summary>
/// 构建 OracleCommand 对象(用来返回一个结果集，而不是一个整数值)
/// </summary>
/// <param name="connection">数据库连接</param>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <returns>OracleCommand</returns>
private static OracleCommand BuildQueryCommand(OracleConnection connection,string storedProcName, IDataParameter[] parameters)
{  
OracleCommand command = new OracleCommand( storedProcName, connection );
command.CommandType = CommandType.StoredProcedure;
foreach (OracleParameter parameter in parameters)
{
command.Parameters.Add( parameter );
}
return command;  
}
/// <summary>
/// 执行存储过程，返回影响的行数  
/// </summary>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <param name="rowsAffected">影响的行数</param>
/// <returns></returns>
public static int RunProcedure(string storedProcName, IDataParameter[] parameters, out int rowsAffected )
{
using (OracleConnection connection = new OracleConnection(connectionString))
{
int result;
connection.Open();
OracleCommand command = BuildIntCommand(connection,storedProcName, parameters );
rowsAffected = command.ExecuteNonQuery();
result = (int)command.Parameters["ReturnValue"].Value;
//Connection.Close();
return result;
}
}
/// <summary>
/// 创建 OracleCommand 对象实例(用来返回一个整数值)
/// </summary>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <returns>OracleCommand 对象实例</returns>
private static OracleCommand BuildIntCommand(OracleConnection connection,string storedProcName, IDataParameter[] parameters)
{
OracleCommand command = BuildQueryCommand(connection,storedProcName, parameters );
command.Parameters.Add( new OracleParameter ( "ReturnValue",
                OracleType.Int32, 4, ParameterDirection.ReturnValue,
false,0,0,string.Empty,DataRowVersion.Default,null ));
return command;
}
#endregion
 
}

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