从Oracle DB检索映像 [英] Retrieve image from Oracle DB
问题描述
所以,我正在使用网络API来检索图像!但是,在数据库中,该图像是LongRaw.我在谷歌上看到我需要使用OracleDbType.Blob 但是,当我尝试使用它时,
So, i am using a web api to retrieve a image!! But, at the DB the image is a LongRaw. Im seeing at the google that i need to use the OracleDbType.Blob But, when i try to use this,
public IEnumerable<FotoEnvolvido> GetFoto(string suspid)
{
DataSet lretorno = new DataSet();
string connectionString = GetConnectionString();
using (OracleConnection connection = new OracleConnection())
{
connection.ConnectionString = connectionString;
OracleDataReader reader = null;
OracleCommand cmd = new OracleCommand();
cmd.InitialLONGFetchSize = 50000;
cmd.Connection = connection;
cmd = new OracleCommand("MOBILE.XAPIMANDADOMOBILE.BUSCAFOTO", connection);
cmd.CommandType = CommandType.StoredProcedure;
//variáveis entrada
cmd.Parameters.Add(new OracleParameter("SUSPID", suspid));
//variáveis de saida
cmd.Parameters.Add(new OracleParameter("oretorno", OracleDbType.Blob)).Direction = ParameterDirection.Output;
connection.Open();
cmd.ExecuteNonQuery();
OracleDataAdapter da = new OracleDataAdapter(cmd);
da.Fill(lretorno);
reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
//CRIO A LISTA
lretorno.Load(reader, LoadOption.OverwriteChanges, "BUSCAFOTO");
connection.Close();
connection.Dispose();
var teste = lretorno.Tables[0].AsEnumerable().Select(row => new FotoEnvolvido
{
FOTO = (byte[])(row["FOTO"]),
});
return teste;
}
}
我在cmd.ExecuteNonQuery()上出错:
i have a error on cmd.ExecuteNonQuery() :
"ORA-06550: linha 1, coluna 7:\nPLS-00306: número errado ou tipos de argumentos na chamada para 'BUSCAFOTO'\nORA-06550: linha 1, coluna 7:\nPL/SQL: Statement ignored"
Oracle.ManagedDataAccess.Client.OracleException was unhandled by user code
DataSource=""
ErrorCode=-2147467259
HResult=-2147467259
IsRecoverable=false
Message=ORA-06550: linha 1, coluna 7:
PLS-00306: número errado ou tipos de argumentos na chamada para 'BUSCAFOTO'
ORA-06550: linha 1, coluna 7:
PL/SQL: Statement ignored
Number=6550
Procedure=""
Source=Oracle Data Provider for .NET, Managed Driver
StackTrace:
em OracleInternal.ServiceObjects.OracleCommandImpl.VerifyExecution(OracleConnectionImpl connectionImpl, Int32& cursorId, Boolean bThrowArrayBindRelatedErrors, OracleException& exceptionForArrayBindDML, Boolean& hasMoreRowsInDB, Boolean bFirstIterationDone)
em OracleInternal.ServiceObjects.OracleCommandImpl.VerifyExecution(OracleConnectionImpl connectionImpl, Int32& cursorId, Boolean bThrowArrayBindRelatedErrors, OracleException& exceptionForArrayBindDML, Boolean bFirstIterationDone)
em OracleInternal.ServiceObjects.OracleCommandImpl.ExecuteNonQuery(String commandText, OracleParameterCollection paramColl, CommandType commandType, OracleConnectionImpl connectionImpl, Int32 longFetchSize, Int64 clientInitialLOBFS, OracleDependencyImpl orclDependencyImpl, Int64[]& scnFromExecution, OracleParameterCollection& bindByPositionParamColl, Boolean& bBindParamPresent, OracleException& exceptionForArrayBindDML, Boolean isFromEF)
em Oracle.ManagedDataAccess.Client.OracleCommand.ExecuteNonQuery()
em WebApiApp.Controllers.FotoController.GetFoto(String suspid) na C:\Users\50216740\Documents\Visual Studio 2015\Projects\AppMobilePCRJ\AppMobilePCRJ\WebApiApp\Controllers\FotoController.cs:linha 49
em lambda_method(Closure , Object , Object[] )
em System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass10.<GetExecutor>b__9(Object instance, Object[] methodParameters)
em System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.Execute(Object instance, Object[] arguments)
em System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync(HttpControllerContext controllerContext, IDictionary`2 arguments, CancellationToken cancellationToken)
InnerException:
如果我像其他获取字符串的Web API一样使用OracleDbType.RefCursor,请不要给我这个错误...问题是参数来了[[" ISUSPID:0," FOTO":"}],即使在DB上也给我带来了图像!
我犯错了,那就是杰森的FOTO是空的?
What i am doind wrong, thats the FOTO is empty on Json ???
推荐答案
我不确定lretorno.Load(...)正在做什么以读取数据,但是使用select语句的sudo代码示例可能会为您提供帮助...我一直必须专门获取blob并将其读出以获取过去的字节.
I'm not sure what lretorno.Load(...) is doing to read the data, but this sudo code sample using a select statement might help you... I've always had to specifically get the blob and read it out to get the bytes in the past.
检索 LONG RAW 数据类型
var imgCmd = new OracleCommand("SELECT photo FROM photos WHERE photo_id = 1", _con);
imgCmd.InitialLONGFetchSize = -1; // Retrieve the entire image during select instead of possible two round trips to DB
var reader = imgCmd.ExecuteReader();
if (reader.Read()) {
// Fetch the LONG RAW
OracleBinary imgBinary = reader.GetOracleBinary(0);
// Get the bytes from the binary obj
byte[] imgBytes = imgBinary.IsNull ? null : imgBinary.Value;
}
reader.Close();
获取 BLOB 数据类型
var imgCmd = new OracleCommand("SELECT photo FROM photos WHERE photo_id = 1", _con);
var reader = imgCmd.ExecuteReader();
if (reader.Read()) {
// Fetch the blob
OracleBlob imgBlob = reader.GetOracleBlob(0);
// Create byte array to read the blob into
byte[] imgBytes = new byte[imgBlob.Length];
// Read the blob into the byte array
imgBlob.Read(imgBytes, 0, imgBlob.Length);
}
reader.Close();
这篇关于从Oracle DB检索映像的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!