IBatis返回DataTable，DataSet
ibatis.net QueryForDataTable
完整的为ibatis.net 引入datatable支持要改动很多地方,所以描述的是最小化的改动.不过我们可以大概了解一下比较完整的集成要做那些事情.
ibatis.net 的基本运行原理就是获得一个reader后,然后进行循环,对每条记录使用ResultStrategy中的对应实现进行处理,然后返回到结果集.因此,首先,需要实现一个DataTableStrategy 用来为每条记录产生一个新DataRow. 大家可以看到,下面的实现已经绕开了ibatis.net的处理逻辑.
你可以在网上google到一些ibatis返回dataset的代码,可在最新的版本1.6 ibatis.net 这些代码都无法工作,这是因为RequestScope.IDbCommand现在返回的是一个DbCommandDecorator对象实例(一个实现IDbCommand接口并代理一个具体的IDbCommand实现的对象),而DataAdapter的实现,需要对应的idbcommand实现,如 SqlDataAdapter需要SqlCommand.因此,如下代码会导致cast错误
Mapper.LocalSession.CreateDataAdapter(scope.IDbCommand).Fill(dataTable);
这里有两种解法,一是使用datatable.Load方法来装载IDbCommand.ExecuteReader的返回结果,这是可行的
其次是利用反射,实际的idbcommand在DbCommandDecorator中被保存为_innerDbCommand field ,下面是两种实现. 大约的感觉,如果你在意性能的话,第一种会快些
/// <summary>
/// 查询返回DatatTable
/// </summary>
/// <param name="statementName"></param>
/// <param name="parameterObject"></param>
/// <returns></returns>
public DataTable QueryForDataTable(string statementName, object parameterObject)
{
bool isSessionLocal = false;
ISqlMapSession session = SqlMap.LocalSession;
DataTable dataTable = null;
if (session == null)
{
session = SqlMap.CreateSqlMapSession();
isSessionLocal = true;
}
try
{
IMappedStatement statement = SqlMap.GetMappedStatement(statementName);
dataTable = new DataTable(statementName);
RequestScope request = statement.Statement.Sql.GetRequestScope(statement, parameterObject, session);
statement.PreparedCommand.Create(request, session, statement.Statement, parameterObject);
using (request.IDbCommand)
{
dataTable.Load(request.IDbCommand.ExecuteReader());
}
}
catch
{
throw;
}
finally
{
if (isSessionLocal)
{
session.CloseConnection();
}
}
return dataTable;
}
查询返回DatatTable
/// <summary>
/// iBatisNet 1.6版本 返回DataSet
/// </summary>
/// <param name="statementName"></param>
/// <param name="paramObject"></param>
/// <returns></returns>
public DataSet QueryForDataSet(string statementName, object paramObject)
{
DataSet ds = new DataSet();
ISqlMapper mapper = Mapper.Instance();
IMappedStatement statement = mapper.GetMappedStatement(statementName);
if (!mapper.IsSessionStarted)
{
mapper.OpenConnection();
}
RequestScope scope = statement.Statement.Sql.GetRequestScope(statement, paramObject, mapper.LocalSession);
statement.PreparedCommand.Create(scope, mapper.LocalSession, statement.Statement, paramObject);
IDbCommand command = mapper.LocalSession.CreateCommand(CommandType.Text);
command.CommandText = scope.IDbCommand.CommandText;
foreach (IDataParameter pa in scope.IDbCommand.Parameters)
{
command.Parameters.Add(new SqlParameter(pa.ParameterName, pa.Value));
}
mapper.LocalSession.CreateDataAdapter(command).Fill(ds);
return ds;
}
iBatisNet 1.6版本 返回DataSet
public DataSet QueryForDataSet2(string statementName, object parameterObject)
{
bool isSessionLocal = false;
ISqlMapSession session = _sessionStore.LocalSession;
DataSet ds = new DataSet(statementName);
if (session == null)
{
session = CreateSqlMapSession();
isSessionLocal = true;
}
try
{
IMappedStatement statement = GetMappedStatement(statementName);
RequestScope request = statement.Statement.Sql.GetRequestScope(statement, parameterObject, session);
statement.PreparedCommand.Create(request, session, statement.Statement, parameterObject);
FieldInfo info = request.IDbCommand.GetType().GetField("_innerDbCommand", BindingFlags.NonPublic | BindingFlags.Instance);
using (IDbCommand cmd = (IDbCommand)info.GetValue(request.IDbCommand))
{
session.CreateDataAdapter(cmd).Fill(ds);
}
}
catch
{
throw;
}
finally
{
if (isSessionLocal)
{
session.CloseConnection();
}
}
return ds;
}
利用反射返回DataSet
以下是1.6.1版本之前返回DataTable的方法。
private IDbCommand GetDbCommand(string statementName, object paramObject)
{
IStatement statement = sqlMap.GetMappedStatement(statementName).Statement;
IMappedStatement mapStatement = sqlMap.GetMappedStatement(statementName);
IDalSession session = new SqlMapSession(sqlMap);
if (sqlMap.LocalSession != null)
{
session = sqlMap.LocalSession;
}
else
{
session = sqlMap.OpenConnection();
}
RequestScope request = statement.Sql.GetRequestScope(mapStatement, paramObject, session);
mapStatement.PreparedCommand.Create(request, session, statement, paramObject);
return request.IDbCommand;
}
获取DbCommand
这种返回DataTable的方式，容易引起Sql注入，因为xml文件中，sql语句需要使用$作为占位符。
/// <summary>
/// 通用的以DataTable的方式得到Select的结果(xml文件中参数要使用$标记的占位参数)
/// </summary>
/// <param name="statementName">语句ID</param>
/// <param name="paramObject">语句所需要的参数</param>
/// <returns>得到的DataTable</returns>
protected DataTable ExecuteQueryForDataTable(string statementName, object paramObject)
{
DataSet ds = new DataSet();
bool isSessionLocal = false;
IDalSession session = sqlMap.LocalSession;
if (session == null)
{
session = new SqlMapSession(sqlMap);
session.OpenConnection();
isSessionLocal = true;
}
IDbCommand cmd = GetDbCommand(statementName, paramObject);
try
{
cmd.Connection = session.Connection;
IDbDataAdapter adapter = session.CreateDataAdapter(cmd);
adapter.Fill(ds);
}
finally
{
if (isSessionLocal)
{
session.CloseConnection();
}
}
];
}
返回DataTable
如果参数中，包含有output参数，则使用下面的方法
/// <summary>
/// 通用的以DataTable的方式得到Select的结果(xml文件中参数要使用$标记的占位参数)
/// </summary>
/// <param name="statementName">语句ID</param>
/// <param name="paramObject">语句所需要的参数</param>
/// <param name="htOutPutParameter)">Output参数值哈希表</param>
/// <returns>得到的DataTable</returns>
protected DataTable ExecuteQueryForDataTable(string statementName, object paramObject, out Hashtable htOutPutParameter)
{
DataSet ds = new DataSet();
bool isSessionLocal = false;
IDalSession session = sqlMap.LocalSession;
if (session == null)
{
session = new SqlMapSession(sqlMap);
session.OpenConnection();
isSessionLocal = true;
}
IDbCommand cmd = GetDbCommand(statementName, paramObject);
try
{
cmd.Connection = session.Connection;
IDbDataAdapter adapter = session.CreateDataAdapter(cmd);
adapter.Fill(ds);
}
finally
{
if (isSessionLocal)
{
session.CloseConnection();
}
}
foreach (IDataParameter parameter in cmd.Parameters)
{
if (parameter.Direction == ParameterDirection.Output)
{
htOutPutParameter[parameter.ParameterName] = parameter.Value;
}
}
];
}
返回DataTable，包含output参数
参考链接：