--- a/CMakeLists.txt	Mon Oct 26 12:30:34 2015 +0100
+++ b/CMakeLists.txt	Mon Oct 26 13:47:50 2015 +0100
@@ -164,6 +164,7 @@
   OrthancServer/Internals/FindScp.cpp
   OrthancServer/Internals/MoveScp.cpp
   OrthancServer/Internals/StoreScp.cpp
+  OrthancServer/LookupIdentifierQuery.cpp
   OrthancServer/LuaScripting.cpp
   OrthancServer/OrthancFindRequestHandler.cpp
   OrthancServer/OrthancHttpHandler.cpp

--- a/OrthancServer/DatabaseWrapper.h	Mon Oct 26 12:30:34 2015 +0100
+++ b/OrthancServer/DatabaseWrapper.h	Mon Oct 26 13:47:50 2015 +0100
@@ -323,11 +323,9 @@
       base_.LookupIdentifierExact(target, level, tag, value);
     }
 
-    virtual void LookupIdentifierWildcard(std::list<int64_t>& target,
-                                          const DicomTag& tag,
-                                          const std::string& value)
+    virtual void LookupIdentifier(const LookupIdentifierQuery& query)
     {
-      base_.LookupIdentifierWildcard(target, tag, value);
+      base_.LookupIdentifier(query);
     }
 
     virtual void GetAllMetadata(std::map<MetadataType, std::string>& target,

--- a/OrthancServer/DatabaseWrapperBase.cpp	Mon Oct 26 12:30:34 2015 +0100
+++ b/OrthancServer/DatabaseWrapperBase.cpp	Mon Oct 26 13:47:50 2015 +0100
@@ -694,9 +694,8 @@
   }
 
 
-  void DatabaseWrapperBase::LookupIdentifierWildcard(std::list<int64_t>& target,
-                                                     const DicomTag& tag,
-                                                     const std::string& value)
+
+  void DatabaseWrapperBase::LookupIdentifier(const LookupIdentifierQuery& query)
   {
     // TODO
     throw OrthancException(ErrorCode_NotImplemented);

--- a/OrthancServer/DatabaseWrapperBase.h	Mon Oct 26 12:30:34 2015 +0100
+++ b/OrthancServer/DatabaseWrapperBase.h	Mon Oct 26 13:47:50 2015 +0100
@@ -39,6 +39,7 @@
 #include "../Core/SQLite/Connection.h"
 #include "../OrthancServer/ExportedResource.h"
 #include "../OrthancServer/ServerIndexChange.h"
+#include "LookupIdentifierQuery.h"
 #include "ServerEnumerations.h"
 
 #include <list>
@@ -195,9 +196,7 @@
                                const DicomTag& tag,
                                const std::string& value);
 
-    void LookupIdentifierWildcard(std::list<int64_t>& target,
-                                  const DicomTag& tag,
-                                  const std::string& value);
+    void LookupIdentifier(const LookupIdentifierQuery& query);
   };
 }
 

--- a/OrthancServer/IDatabaseWrapper.h	Mon Oct 26 12:30:34 2015 +0100
+++ b/OrthancServer/IDatabaseWrapper.h	Mon Oct 26 13:47:50 2015 +0100
@@ -44,6 +44,8 @@
 
 namespace Orthanc
 {
+  class LookupIdentifierQuery;
+
   class IDatabaseWrapper : public boost::noncopyable
   {
   public:
@@ -151,28 +153,7 @@
                                        const DicomTag& tag,
                                        const std::string& value) = 0;
 
-    /**
-     * Primitive for wildcard matching, as defined in DICOM:
-     * http://dicom.nema.org/dicom/2013/output/chtml/part04/sect_C.2.html#sect_C.2.2.2.4
-     * 
-     * "Any occurrence of an "*" or a "?", then "*" shall match any
-     * sequence of characters (including a zero length value) and "?"
-     * shall match any single character. This matching is case
-     * sensitive, except for Attributes with an PN Value
-     * Representation (e.g., Patient Name (0010,0010))."
-     * 
-     * Pay attention to the fact that "*" (resp. "?") generally
-     * corresponds to "%" (resp. "_") in primitive LIKE of SQL. The
-     * values "%", "_", "\" should in the user request should
-     * respectively be escaped as "\%", "\_" and "\\".
-     * 
-     * This matching must be case sensitive: The special case of PN VR
-     * is taken into consideration by normalizing the query string in
-     * method "ServerIndex::LookupIdentifierWildcard()".
-     **/
-    virtual void LookupIdentifierWildcard(std::list<int64_t>& target,
-                                          const DicomTag& tag,
-                                          const std::string& value) = 0;
+    virtual void LookupIdentifier(const LookupIdentifierQuery& query) = 0;
 
     virtual bool LookupMetadata(std::string& target,
                                 int64_t id,

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancServer/LookupIdentifierQuery.cpp	Mon Oct 26 13:47:50 2015 +0100
@@ -0,0 +1,205 @@
+/**
+ * Orthanc - A Lightweight, RESTful DICOM Store
+ * Copyright (C) 2012-2015 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * In addition, as a special exception, the copyright holders of this
+ * program give permission to link the code of its release with the
+ * OpenSSL project's "OpenSSL" library (or with modified versions of it
+ * that use the same license as the "OpenSSL" library), and distribute
+ * the linked executables. You must obey the GNU General Public License
+ * in all respects for all of the code used other than "OpenSSL". If you
+ * modify file(s) with this exception, you may extend this exception to
+ * your version of the file(s), but you are not obligated to do so. If
+ * you do not wish to do so, delete this exception statement from your
+ * version. If you delete this exception statement from all source files
+ * in the program, then also delete it here.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#include "PrecompiledHeadersServer.h"
+#include "LookupIdentifierQuery.h"
+
+#include "../Core/OrthancException.h"
+
+
+#include <cassert>
+
+
+
+namespace Orthanc
+{
+  static const DicomTag patientIdentifiers[] = 
+  {
+    DICOM_TAG_PATIENT_ID,
+    DICOM_TAG_PATIENT_NAME,
+    DICOM_TAG_PATIENT_BIRTH_DATE
+  };
+
+  static const DicomTag studyIdentifiers[] = 
+  {
+    DICOM_TAG_PATIENT_ID,
+    DICOM_TAG_PATIENT_NAME,
+    DICOM_TAG_PATIENT_BIRTH_DATE,
+    DICOM_TAG_STUDY_INSTANCE_UID,
+    DICOM_TAG_ACCESSION_NUMBER,
+    DICOM_TAG_STUDY_DESCRIPTION,
+    DICOM_TAG_STUDY_DATE
+  };
+
+  static const DicomTag seriesIdentifiers[] = 
+  {
+    DICOM_TAG_SERIES_INSTANCE_UID
+  };
+
+  static const DicomTag instanceIdentifiers[] = 
+  {
+    DICOM_TAG_SOP_INSTANCE_UID
+  };
+
+
+  LookupIdentifierQuery::~LookupIdentifierQuery()
+  {
+    for (Constraints::iterator it = constraints_.begin();
+         it != constraints_.end(); ++it)
+    {
+      delete *it;
+    }
+  }
+
+
+
+  void  LookupIdentifierQuery::CheckIndex(size_t index) const
+  {
+    if (index >= constraints_.size())
+    {
+      throw OrthancException(ErrorCode_ParameterOutOfRange);
+    }
+  }
+
+
+  static void LoadIdentifiers(const DicomTag*& tags,
+                              size_t& size,
+                              ResourceType level)
+  {
+    switch (level)
+    {
+      case ResourceType_Patient:
+        tags = patientIdentifiers;
+        size = sizeof(patientIdentifiers) / sizeof(DicomTag);
+        break;
+
+      case ResourceType_Study:
+        tags = studyIdentifiers;
+        size = sizeof(studyIdentifiers) / sizeof(DicomTag);
+        break;
+
+      case ResourceType_Series:
+        tags = seriesIdentifiers;
+        size = sizeof(seriesIdentifiers) / sizeof(DicomTag);
+        break;
+
+      case ResourceType_Instance:
+        tags = instanceIdentifiers;
+        size = sizeof(instanceIdentifiers) / sizeof(DicomTag);
+        break;
+
+      default:
+        throw OrthancException(ErrorCode_ParameterOutOfRange);
+    }
+  }
+
+
+  bool LookupIdentifierQuery::IsIdentifier(const DicomTag& tag) const
+  {
+    const DicomTag* tags;
+    size_t size;
+
+    LoadIdentifiers(tags, size, level_);
+
+    for (size_t i = 0; i < size; i++)
+    {
+      if (tag == tags[i])
+      {
+        return true;
+      }
+    }
+
+    return false;
+  }
+
+
+  void LookupIdentifierQuery::AddConstraint(DicomTag tag,
+                                            IdentifierConstraintType type,
+                                            const std::string& value)
+  {
+    assert(IsIdentifier(tag));
+    constraints_.push_back(new Constraint(tag, type, NormalizeIdentifier(value)));
+  }
+
+
+  const DicomTag& LookupIdentifierQuery::GetTag(size_t index) const
+  {
+    CheckIndex(index);
+    return constraints_[index]->tag_;
+  }
+
+
+  IdentifierConstraintType  LookupIdentifierQuery::GetType(size_t index) const
+  {
+    CheckIndex(index);
+    return constraints_[index]->type_;
+  }
+
+
+  const std::string& LookupIdentifierQuery::GetValue(size_t index) const
+  {
+    CheckIndex(index);
+    return constraints_[index]->value_;
+  }
+
+
+  std::string LookupIdentifierQuery::NormalizeIdentifier(const std::string& value)
+  {
+    std::string s = Toolbox::ConvertToAscii(Toolbox::StripSpaces(value));
+    Toolbox::ToUpperCase(s);
+    return s;
+  }
+
+
+  void LookupIdentifierQuery::StoreIdentifiers(IDatabaseWrapper& database,
+                                               int64_t resource,
+                                               ResourceType level,
+                                               const DicomMap& map)
+  {
+    const DicomTag* tags;
+    size_t size;
+
+    LoadIdentifiers(tags, size, level);
+
+    for (size_t i = 0; i < size; i++)
+    {
+      const DicomValue* value = map.TestAndGetValue(tags[i]);
+      if (value != NULL &&
+          !value->IsNull() &&
+          !value->IsBinary())
+      {
+        std::string s = NormalizeIdentifier(value->GetContent());
+        database.SetIdentifierTag(resource, tags[i], s);
+      }
+    }
+  }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancServer/LookupIdentifierQuery.h	Mon Oct 26 13:47:50 2015 +0100
@@ -0,0 +1,123 @@
+/**
+ * Orthanc - A Lightweight, RESTful DICOM Store
+ * Copyright (C) 2012-2015 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * In addition, as a special exception, the copyright holders of this
+ * program give permission to link the code of its release with the
+ * OpenSSL project's "OpenSSL" library (or with modified versions of it
+ * that use the same license as the "OpenSSL" library), and distribute
+ * the linked executables. You must obey the GNU General Public License
+ * in all respects for all of the code used other than "OpenSSL". If you
+ * modify file(s) with this exception, you may extend this exception to
+ * your version of the file(s), but you are not obligated to do so. If
+ * you do not wish to do so, delete this exception statement from your
+ * version. If you delete this exception statement from all source files
+ * in the program, then also delete it here.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#pragma once
+
+#include "ServerEnumerations.h"
+#include "IDatabaseWrapper.h"
+
+#include <vector>
+#include <boost/noncopyable.hpp>
+
+namespace Orthanc
+{
+  /**
+   * Primitive for wildcard matching, as defined in DICOM:
+   * http://dicom.nema.org/dicom/2013/output/chtml/part04/sect_C.2.html#sect_C.2.2.2.4
+   * 
+   * "Any occurrence of an "*" or a "?", then "*" shall match any
+   * sequence of characters (including a zero length value) and "?"
+   * shall match any single character. This matching is case
+   * sensitive, except for Attributes with an PN Value
+   * Representation (e.g., Patient Name (0010,0010))."
+   * 
+   * Pay attention to the fact that "*" (resp. "?") generally
+   * corresponds to "%" (resp. "_") in primitive LIKE of SQL. The
+   * values "%", "_", "\" should in the user request should
+   * respectively be escaped as "\%", "\_" and "\\".
+   * 
+   * This matching must be case sensitive: The special case of PN VR
+   * is taken into consideration by normalizing the query string in
+   * method "NormalizeIdentifier()".
+   **/
+
+
+
+  class LookupIdentifierQuery : public boost::noncopyable
+  {
+  private:
+    struct Constraint
+    {
+      DicomTag                  tag_;
+      IdentifierConstraintType  type_;
+      std::string               value_;
+
+      Constraint(const DicomTag& tag,
+                 IdentifierConstraintType type,
+                 const std::string& value) : 
+        tag_(tag),
+        type_(type),
+        value_(value)
+      {
+      }
+    };
+
+    typedef std::vector<Constraint*>  Constraints;
+
+    ResourceType  level_;
+    Constraints   constraints_;
+
+    void CheckIndex(size_t index) const;
+
+    static std::string NormalizeIdentifier(const std::string& value);
+
+  public:
+    LookupIdentifierQuery(ResourceType level) : level_(level)
+    {
+    }
+
+    ~LookupIdentifierQuery();
+
+    bool IsIdentifier(const DicomTag& tag) const;
+
+    void AddConstraint(DicomTag tag,
+                       IdentifierConstraintType type,
+                       const std::string& value);
+
+    size_t GetSize()
+    {
+      return constraints_.size();
+    }
+
+    const DicomTag& GetTag(size_t index) const;
+
+    IdentifierConstraintType  GetType(size_t index) const;
+
+    const std::string& GetValue(size_t index) const;
+
+    static void StoreIdentifiers(IDatabaseWrapper& database,
+                                 int64_t resource,
+                                 ResourceType level,
+                                 const DicomMap& map);
+    
+  };
+}

--- a/OrthancServer/ServerEnumerations.h	Mon Oct 26 12:30:34 2015 +0100
+++ b/OrthancServer/ServerEnumerations.h	Mon Oct 26 13:47:50 2015 +0100
@@ -125,6 +125,14 @@
                                  DicomToJsonFlags_ConvertBinaryToNull)
   };
 
+  enum IdentifierConstraintType
+  {
+    IdentifierConstraintType_Equal,
+    IdentifierConstraintType_LessOrEqual,
+    IdentifierConstraintType_GeaterOrEqual,
+    IdentifierConstraintType_Wildcard        /* "*" or "?" are the only allowed wildcards */
+  };
+
 
   /**
    * WARNING: Do not change the explicit values in the enumerations

--- a/OrthancServer/ServerToolbox.cpp	Mon Oct 26 12:30:34 2015 +0100
+++ b/OrthancServer/ServerToolbox.cpp	Mon Oct 26 13:47:50 2015 +0100
@@ -38,6 +38,7 @@
 #include "../Core/Logging.h"
 #include "../Core/OrthancException.h"
 #include "ParsedDicomFile.h"
+#include "LookupIdentifierQuery.h"
 
 #include <cassert>
 
@@ -193,45 +194,6 @@
     }
 
 
-    static void SetIdentifierTagInternal(IDatabaseWrapper& database,
-                                         int64_t resource,
-                                         const DicomMap& tags,
-                                         const DicomTag& tag)
-    {
-      const DicomValue* value = tags.TestAndGetValue(tag);
-      if (value != NULL &&
-          !value->IsNull() &&
-          !value->IsBinary())
-      {
-        std::string s = value->GetContent();
-
-        if (tag != DICOM_TAG_PATIENT_ID &&
-            tag != DICOM_TAG_STUDY_INSTANCE_UID &&
-            tag != DICOM_TAG_SERIES_INSTANCE_UID &&
-            tag != DICOM_TAG_SOP_INSTANCE_UID &&
-            tag != DICOM_TAG_ACCESSION_NUMBER)
-        {
-          s = NormalizeTagForWildcard(s);
-        }
-
-        database.SetIdentifierTag(resource, tag, s);
-      }
-    }
-
-
-    static void AttachPatientInformation(IDatabaseWrapper& database,
-                                         int64_t resource,
-                                         const DicomMap& dicomSummary)
-    {
-      DicomMap tags;
-      dicomSummary.ExtractPatientInformation(tags);
-      SetIdentifierTagInternal(database, resource, tags, DICOM_TAG_PATIENT_ID);
-      SetIdentifierTagInternal(database, resource, tags, DICOM_TAG_PATIENT_NAME);
-      SetIdentifierTagInternal(database, resource, tags, DICOM_TAG_PATIENT_BIRTH_DATE);
-      SetMainDicomTagsInternal(database, resource, tags);
-    }
-
-
     void SetMainDicomTags(IDatabaseWrapper& database,
                           int64_t resource,
                           ResourceType level,
@@ -239,33 +201,30 @@
     {
       // WARNING: The database should be locked with a transaction!
 
+      LookupIdentifierQuery::StoreIdentifiers(database, resource, level, dicomSummary);
+
       DicomMap tags;
 
       switch (level)
       {
         case ResourceType_Patient:
-          AttachPatientInformation(database, resource, dicomSummary);
+          dicomSummary.ExtractPatientInformation(tags);
           break;
 
         case ResourceType_Study:
           // Duplicate the patient tags at the study level (new in Orthanc 0.9.5 - db v6)
-          AttachPatientInformation(database, resource, dicomSummary);
+          dicomSummary.ExtractPatientInformation(tags);
+          SetMainDicomTagsInternal(database, resource, tags);
 
           dicomSummary.ExtractStudyInformation(tags);
-          SetIdentifierTagInternal(database, resource, tags, DICOM_TAG_STUDY_INSTANCE_UID);
-          SetIdentifierTagInternal(database, resource, tags, DICOM_TAG_ACCESSION_NUMBER);
-          SetIdentifierTagInternal(database, resource, tags, DICOM_TAG_STUDY_DESCRIPTION);
-          SetIdentifierTagInternal(database, resource, tags, DICOM_TAG_STUDY_DATE);
           break;
 
         case ResourceType_Series:
           dicomSummary.ExtractSeriesInformation(tags);
-          SetIdentifierTagInternal(database, resource, tags, DICOM_TAG_SERIES_INSTANCE_UID);
           break;
 
         case ResourceType_Instance:
           dicomSummary.ExtractInstanceInformation(tags);
-          SetIdentifierTagInternal(database, resource, tags, DICOM_TAG_SOP_INSTANCE_UID);
           break;
 
         default:
@@ -374,13 +333,5 @@
         Toolbox::SetMainDicomTags(database, resource, level, dicomSummary);
       }
     }
-
-
-    std::string NormalizeTagForWildcard(const std::string& value)
-    {
-      std::string s = Toolbox::ConvertToAscii(Toolbox::StripSpaces(value));
-      Toolbox::ToUpperCase(s);
-      return s;
-    }
   }
 }

--- a/OrthancServer/ServerToolbox.h	Mon Oct 26 12:30:34 2015 +0100
+++ b/OrthancServer/ServerToolbox.h	Mon Oct 26 13:47:50 2015 +0100
@@ -59,7 +59,5 @@
     void ReconstructMainDicomTags(IDatabaseWrapper& database,
                                   IStorageArea& storageArea,
                                   ResourceType level);
-
-    std::string NormalizeTagForWildcard(const std::string& value);
   }
 }

--- a/Plugins/Engine/OrthancPluginDatabase.cpp	Mon Oct 26 12:30:34 2015 +0100
+++ b/Plugins/Engine/OrthancPluginDatabase.cpp	Mon Oct 26 13:47:50 2015 +0100
@@ -646,9 +646,7 @@
   }
 
 
-  void OrthancPluginDatabase::LookupIdentifierWildcard(std::list<int64_t>& target,
-                                                       const DicomTag& tag,
-                                                       const std::string& value)
+  void OrthancPluginDatabase::LookupIdentifier(const LookupIdentifierQuery& query)
   {
     // TODO
     throw OrthancException(ErrorCode_NotImplemented);

--- a/Plugins/Engine/OrthancPluginDatabase.h	Mon Oct 26 12:30:34 2015 +0100
+++ b/Plugins/Engine/OrthancPluginDatabase.h	Mon Oct 26 13:47:50 2015 +0100
@@ -208,9 +208,7 @@
                                        const DicomTag& tag,
                                        const std::string& value);
 
-    virtual void LookupIdentifierWildcard(std::list<int64_t>& target,
-                                          const DicomTag& tag,
-                                          const std::string& value);
+    virtual void LookupIdentifier(const LookupIdentifierQuery& query);
 
     virtual bool LookupMetadata(std::string& target,
                                 int64_t id,