using System;
using System.Configuration;
using System.Data;
using System.Data.OracleClient;
using System.Collections;
using System.Web;
namespace Game.DBUtility
{
/// <summary>
/// A helper class used to execute queries against an Oracle database
/// 一个用来帮助执行Oracle数据库操作的类
/// </summary>
public abstract class OracleHelper
{
// Read the connection strings from the configuration file
//从配置文件中读取数据库连接字串
public static readonly string ConnectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
public static readonly string ConnectionStringLocalTransaction = ConfigurationManager.AppSettings["OraConnString1"];
public static readonly string ConnectionStringInventoryDistributedTransaction = ConfigurationManager.AppSettings["OraConnString2"];
public static readonly string ConnectionStringOrderDistributedTransaction = ConfigurationManager.AppSettings["OraConnString3"];
public static readonly string ConnectionStringProfile = ConfigurationManager.AppSettings["OraProfileConnString"];
public static readonly string ConnectionStringMembership = ConfigurationManager.AppSettings["OraMembershipConnString"];
//Create a hashtable for the parameter cached
//为Parameter创建一个哈稀表的缓存
private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable());
/// <summary>
/// Execute a database query which does not include a select
/// 执行一次数据库操作但是不包括查询
/// </summary>
/// 下面为所传递的参数
/// <param name="connString">Connection string to database </param>//数据库的连接字串
/// <param name="cmdType">Command type either stored procedure or SQL </param>//Command 类型为存储过程或者SQL语句
/// <param name="cmdText">Acutall SQL Command</param>
/// <param name="commandParameters">Parameters to bind to the command</param>Parameter 参数
/// <returns></returns>
public static int ExecuteNonQuery(string connectionString, CommandType cmdType, string cmdText, params OracleParameter[] commandParameters)
{
// Create a new Oracle command
//创建一个Oracle command对象
OracleCommand cmd = new OracleCommand();
//Create a connection
//创建一个connection对象
using (OracleConnection connection = new OracleConnection(connectionString))
{
//Prepare the command
//为command做准备，下面有此方法定义
PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
//Execute the command
//执行 command
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return val;
}
}
/// <summary>
/// Execute an OracleCommand (that returns no resultset) against an existing database transaction
/// using the provided parameters.
/// 用parameters执行现有的数据库事务（没有返回值？？）---估计不对
/// </summary>
/// <remarks>
/// e.g.:
/// int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders", new OracleParameter(":prodid", 24));
/// 例子
/// </remarks>
/// <param name="trans">an existing database transaction</param>//一个现有的数据库事务
/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>//command对象类型 （存储过程？？？，文本，其他）
/// <param name="commandText">the stored procedure name or PL/SQL command</param>//存储过程名或者是SQL语句
/// <param name="commandParameters">an array of OracleParamters used to execute the command</param>//用于执行的Paramter数组
/// <returns>an int representing the number of rows affected by the command</returns>//返回的是命令影响的行数
public static int ExecuteNonQuery(OracleTransaction trans, CommandType cmdType, string cmdText, params OracleParameter[] commandParameters)
{
OracleCommand cmd = new OracleCommand();
PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return val;
}
/// <summary>
/// Execute an OracleCommand (that returns no resultset) against an existing database connection
/// using the provided parameters.
/// 执行OracleCommand(没有返回结果)依靠现有的数据库连接利用parameters
/// </summary>
/// <remarks>
/// e.g.:
/// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new OracleParameter(":prodid", 24));
/// 例子
/// </remarks>
/// <param name="conn">an existing database connection</param>//一个现有的数据库连接
/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>//command对象类型 （存储过程？？？，文本，其他）
/// <param name="commandText">the stored procedure name or PL/SQL command</param>//存储过程名或者是SQL语句
/// <param name="commandParameters">an array of OracleParamters used to execute the command</param>//用于执行的Paramter数组
/// <returns>an int representing the number of rows affected by the command</returns>//返回的是命令影响的行数
public static int ExecuteNonQuery(OracleConnection connection, CommandType cmdType, string cmdText, params OracleParameter[] commandParameters)
{
OracleCommand cmd = new OracleCommand();
PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return val;
}
/// <summary>
/// Execute a select query that will return a result set
/// 执行一条查询语句并返回结果
/// </summary>
/// <param name="connString">Connection string</param>//连接字串
/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>//command对象类型 （存储过程？？？，文本，其他）
/// <param name="commandText">the stored procedure name or PL/SQL command</param>//存储过程名或者是SQL语句
/// <param name="commandParameters">an array of OracleParamters used to execute the command</param>//用于执行的Paramter数组
/// <returns></returns>
public static OracleDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params OracleParameter[] commandParameters)
{
//Create the command and connection
//创建一个command和connection对象
OracleCommand cmd = new OracleCommand();
OracleConnection conn = new OracleConnection(connectionString);
try
{
//Prepare the command to execute
//准备执行这个command
PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
//Execute the query, stating that the connection should close when the resulting datareader has been read
//执行查询,当read到数据结果后关闭连接
OracleDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
cmd.Parameters.Clear();
return rdr;
}
catch
{
//If an error occurs close the connection as the reader will not be used and we expect it to close the connection
//当发生错误时或者我们希望时关闭连接
conn.Close();
throw;
}
}
/// <summary>
///
/// </summary>
/// <param name="transaction"></param>
/// <param name="cmdType"></param>
/// <param name="cmdText"></param>
/// <param name="commandParameters"></param>
/// <returns></returns>
public static OracleDataReader ExecuteReaderTrans(OracleTransaction transaction, CommandType cmdType, string cmdText, params OracleParameter[] commandParameters)
{
//Create the command and connection
//创建一个command和connection对象
OracleCommand cmd = new OracleCommand();
//执行内部方法,传入相应参数
PrepareCommand(cmd, transaction.Connection, transaction, cmdType, cmdText, commandParameters);
//Execute the query, stating that the connection should close when the resulting datareader has been read
//执行查询,当read到数据结果后关闭连接
OracleDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
cmd.Parameters.Clear();
return rdr;
}
/// <summary>
/// Execute an OracleCommand that returns the first column of the first record against the database specified in the connection string
/// using the provided parameters.
/// 执行数据库操作并返回第一条记录
/// </summary>
/// <remarks>
/// e.g.:
/// Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new OracleParameter(":prodid", 24));
/// 例子
/// </remarks>
/// <param name="connectionString">a valid connection string for a SqlConnection</param>//一个有效的连接字串
/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>//command对象类型 （存储过程？？？，文本，其他）
/// <param name="commandText">the stored procedure name or PL/SQL command</param>//存储过程名或者是SQL语句
/// <param name="commandParameters">an array of OracleParamters used to execute the command</param>//用于执行的Paramter数组
/// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>//利用Convert.To{Type}转换成想要得到的对象类型
public static object ExecuteScalar(string connectionString, CommandType cmdType, string cmdText, params OracleParameter[] commandParameters)
{
OracleCommand cmd = new OracleCommand();
using (OracleConnection conn = new OracleConnection(connectionString))
{
PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
object val = cmd.ExecuteScalar();
cmd.Parameters.Clear();
return val;
}
}
/// <summary>
/// Execute a OracleCommand (that returns a 1x1 resultset) against the specified SqlTransaction
/// using the provided parameters.
/// 执行OracleCommand(返回一个1*1的结果???)依靠一条指定的事务
/// </summary>
/// <param name="transaction">A valid SqlTransaction</param>//一条有效的数据库事务
/// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>//command对象类型 （存储过程？？？，文本，其他）
/// <param name="commandText">The stored procedure name or PL/SQL command</param>//存储过程名或者是SQL语句
/// <param name="commandParameters">An array of OracleParamters used to execute the command</param>//用于执行的参数数组
/// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>//
public static object ExecuteScalar(OracleTransaction transaction, CommandType commandType, string commandText, params OracleParameter[] commandParameters)
{
if (transaction == null)
throw new ArgumentNullException("transaction");
if (transaction != null && transaction.Connection == null)
throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
// Create a command and prepare it for execution
//创建一个为执行做准备的command对象
OracleCommand cmd = new OracleCommand();
PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters);
// Execute the command & return the results
//执行并返回结果
object retval = cmd.ExecuteScalar();
// Detach the SqlParameters from the command object, so they can be used again
//从Command对象中清除参数以便于可以再次使用
cmd.Parameters.Clear();
return retval;
}
/// <summary>
/// Execute an OracleCommand that returns the first column of the first record against an existing database connection
/// using the provided parameters.
/// 执行OracleCommand返回第一条记录的第一行依靠现有的数据库连接用传入的参数
/// </summary>
/// <remarks>
/// e.g.:
/// Object obj = ExecuteScalar(conn, CommandType.StoredProcedure, "PublishOrders", new OracleParameter(":prodid", 24));
/// 例子
/// </remarks>
/// <param name="conn">an existing database connection</param>//一条现有的数据库连接
/// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>//command对象类型 （存储过程？？？，文本，其他）
/// <param name="commandText">the stored procedure name or PL/SQL command</param>//存储过程名或者是SQL语句
/// <param name="commandParameters">an array of OracleParamters used to execute the command</param>//用于执行的Paramter数组
/// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>//利用Convert.To{Type}转换成想要得到的对象类型
public static object ExecuteScalar(OracleConnection connectionString, CommandType cmdType, string cmdText, params OracleParameter[] commandParameters)
{
OracleCommand cmd = new OracleCommand();
PrepareCommand(cmd, connectionString, null, cmdType, cmdText, commandParameters);
object val = cmd.ExecuteScalar();
cmd.Parameters.Clear();
return val;
}
/// <summary>
/// Add a set of parameters to the cached
/// 在缓存中增加参数
/// </summary>
/// <param name="cacheKey">Key value to look up the parameters</param>//查找KEY值
/// <param name="commandParameters">Actual parameters to cached</param>//缓存中的实际参数
public static void CacheParameters(string cacheKey, params OracleParameter[] commandParameters)
{
parmCache[cacheKey] = commandParameters;
}
/// <summary>
/// Fetch parameters from the cache
/// 从缓存中取得参数
/// </summary>
/// <param name="cacheKey">Key to look up the parameters</param>//查找KEY值
/// <returns></returns>
public static OracleParameter[] GetCachedParameters(string cacheKey)
{
OracleParameter[] cachedParms = (OracleParameter[])parmCache[cacheKey];
if (cachedParms == null)
return null;
// If the parameters are in the cache
//如果参数在缓存中
OracleParameter[] clonedParms = new OracleParameter[cachedParms.Length];
// return a copy of the parameters
//返回一个参数的副本
for (int i = 0, j = cachedParms.Length; i < j; i++)
clonedParms[i] = (OracleParameter)((ICloneable)cachedParms[i]).Clone();
return clonedParms;
}
/// <summary>
/// Internal function to prepare a command for execution by the database
/// 准备执行数据库的一个内部方法
/// </summary>
/// <param name="cmd">Existing command object</param>//现有的command 对象
/// <param name="conn">Database connection object</param>//数据库连接对象
/// <param name="trans">Optional transaction object</param>//可选的OracleTransaction对象
/// <param name="cmdType">Command type, e.g. stored procedure</param>//Command的类型，例如一个存储过程
/// <param name="cmdText">Command test</param>//
/// <param name="commandParameters">Parameters for the command</param>//command 参数
private static void PrepareCommand(OracleCommand cmd, OracleConnection conn, OracleTransaction trans, CommandType cmdType, string cmdText, OracleParameter[] commandParameters)
{
//Open the connection if required
//如果必须则打开一个连接
if (conn.State != ConnectionState.Open)
conn.Open();
//Set up the command
//建立command
cmd.Connection = conn;
cmd.CommandText = cmdText;
cmd.CommandType = cmdType;
//Bind it to the transaction if it exists
//绑定一个事务如果它存在
if (trans != null)
cmd.Transaction = trans;
// Bind the parameters passed in
//做遍历传入对象
if (commandParameters != null)
{
foreach (OracleParameter parm in commandParameters)
cmd.Parameters.Add(parm);
}
}
/// <summary>
/// Converter to use boolean data type with Oracle
/// 把布尔类型转换成值类型????
/// </summary>
/// <param name="value">Value to convert</param>//要转换的值
/// <returns></returns>
public static string OraBit(bool value)
{
if (value)
return "Y";
else
return "N";
}
/// <summary>
/// Converter to use boolean data type with Oracle
/// 把值类型转换成布尔类型????
/// </summary>
/// <param name="value">Value to convert</param>//要转换的值
/// <returns></returns>
public static bool OraBool(string value)
{
if (value.Equals("Y"))
return true;
else
return false;
}
}
}