From efcd12e072d871f2b112d8ab78f6c257c610fbc6 Mon Sep 17 00:00:00 2001
From: Stephan Schwär
Date: Mon, 19 Apr 2021 21:41:26 +0200
Subject: [server] Remove redundant null values in sql query

---
 .../openslx/bwlp/sat/database/mappers/DbImage.java | 53 +++++++---------------
 1 file changed, 17 insertions(+), 36 deletions(-)

diff --git a/dozentenmodulserver/src/main/java/org/openslx/bwlp/sat/database/mappers/DbImage.java b/dozentenmodulserver/src/main/java/org/openslx/bwlp/sat/database/mappers/DbImage.java
index 2c58773a..8482087a 100644
--- a/dozentenmodulserver/src/main/java/org/openslx/bwlp/sat/database/mappers/DbImage.java
+++ b/dozentenmodulserver/src/main/java/org/openslx/bwlp/sat/database/mappers/DbImage.java
@@ -88,17 +88,11 @@ public class DbImage {
 	public static ImageDetailsRead getImageDetails(UserInfo user, String imageBaseId)
 			throws TNotFoundException, SQLException {
 		try (MysqlConnection connection = Database.getConnection()) {
-
-			// if Student is trying to download only needed information is filled
 			MysqlStatement stmt = null;
-			if (user.role == Role.STUDENT) 
+			// Students should only be able to request a download of an image. Therefore not all information is needed for this task.
+			if (user.role == Role.STUDENT)
 			{
-				// Todo remove evaluate and minimize the null placeholders
-				stmt = connection.prepareStatement("SELECT i.imagebaseid, i.latestversionid,"
-					+ " null, null, null, null, null, null, null, null,"
-					+ " null, null,"
-					+ " null, null, null, null,"
-					+ " null, null, null, null"
+				stmt = connection.prepareStatement("SELECT i.imagebaseid, i.latestversionid"
 					+ " FROM imagebase i"
 					+ " LEFT JOIN imagepermission perm ON (i.imagebaseid = perm.imagebaseid AND perm.userid = :userid)"
 					+ " WHERE i.imagebaseid = :imagebaseid");
@@ -111,10 +105,7 @@ public class DbImage {
 					+ " FROM imagebase i"
 					+ " LEFT JOIN imagepermission perm ON (i.imagebaseid = perm.imagebaseid AND perm.userid = :userid)"
 					+ " WHERE i.imagebaseid = :imagebaseid");
-					
 			}
-
-			// if Student is trying to download only needed information is filled
 			stmt.setString("userid", user == null ? "-" : user.userId);
 			stmt.setString("imagebaseid", imageBaseId);
 			ResultSet rs = stmt.executeQuery();
@@ -125,16 +116,15 @@ public class DbImage {
 			List<ImageVersionDetails> versions = getImageVersions(connection, imageBaseId, user);
 
 			ImageDetailsRead image;
-			
 			if (user.role == Role.STUDENT) {
+				// Students should only have download permissions.
+				// todo evaluate if this is needed and if there is a nicer way to create ImageDetailsRead object
 				ImagePermissions defaultPermissions = new ImagePermissions(false, true, false, false);
-
 				image = new ImageDetailsRead(rs.getString("imagebaseid"),
 					rs.getString("latestversionid"), versions, imageBaseId, imageBaseId, tags, 0, imageBaseId, 0, 0, imageBaseId, imageBaseId, null, false, defaultPermissions);
 				image.setUserPermissions(defaultPermissions);
 			} else {
 				ImagePermissions defaultPermissions = DbImagePermissions.fromResultSetDefault(rs);
-
 				image = new ImageDetailsRead(rs.getString("imagebaseid"),
 						rs.getString("latestversionid"), versions, rs.getString("displayname"),
 						rs.getString("description"), tags, rs.getInt("osid"), rs.getString("virtid"),
@@ -142,7 +132,6 @@ public class DbImage {
 						rs.getString("updaterid"), toShareMode(rs.getString("sharemode")),
 						rs.getByte("istemplate") != 0, defaultPermissions);
 				image.setUserPermissions(DbImagePermissions.fromResultSetUser(rs));
-
 			}
 			User.setCombinedUserPermissions(image, user);
 			return image;
@@ -297,28 +286,20 @@ public class DbImage {
 		}
 		stmt.setString("imagebaseid", imageBaseId);
 		ResultSet rs = stmt.executeQuery();
-		if (user.role == Role.STUDENT) {
-			while (rs.next()) {
-				String imageVersionId = rs.getString("imageversionid");
-				versionList.add(new ImageVersionDetails(imageVersionId, rs.getLong("createtime"),
-				// todo evaluate this empty string for uploaderid
-						rs.getLong("expiretime"), rs.getLong("filesize"), "",
-						rs.getByte("isrestricted") != 0, rs.getByte("isvalid") != 0,
-						rs.getByte("isprocessed") != 0, DbSoftwareTag.getImageVersionSoftwareList(connection,
-								imageVersionId)));
-			}
-			
-		} else {
-			while (rs.next()) {
-				String imageVersionId = rs.getString("imageversionid");
-				versionList.add(new ImageVersionDetails(imageVersionId, rs.getLong("createtime"),
-						rs.getLong("expiretime"), rs.getLong("filesize"), rs.getString("uploaderid"),
-						rs.getByte("isrestricted") != 0, rs.getByte("isvalid") != 0,
-						rs.getByte("isprocessed") != 0, DbSoftwareTag.getImageVersionSoftwareList(connection,
-								imageVersionId)));
+		
+		while (rs.next()) {
+			String imageVersionId = rs.getString("imageversionid");
+			String uploaderID = "";
+			// Only student doesn't know the uploaderid
+			if (user.role != Role.STUDENT) {
+				uploaderID = rs.getString("uploaderid");
 			}
+			versionList.add(new ImageVersionDetails(imageVersionId, rs.getLong("createtime"),
+					rs.getLong("expiretime"), rs.getLong("filesize"), uploaderID,
+					rs.getByte("isrestricted") != 0, rs.getByte("isvalid") != 0,
+					rs.getByte("isprocessed") != 0, DbSoftwareTag.getImageVersionSoftwareList(connection,
+							imageVersionId)));
 		}
-		
 		stmt.close();
 		return versionList;
 	}
-- 
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