OO-2405: better sorting of keyword, coverage and additional informations in question pool

src/main/java/org/olat/modules/qpool/manager/QItemQueriesDAO.java

@@ -375,18 +375,43 @@ public class QItemQueriesDAO {
 			boolean asc = orderBy[0].isAsc();
 			sb.append(" order by ");
 			switch(sortKey) {
-				case "itemType": sb.append(dbRef).append(".type.type"); break;
-				case "marks": sb.append("marks"); break;
-				case "rating": sb.append("rating"); break;
-				default: sb.append(dbRef).append(".").append(sortKey); break;
-			}
-			if(asc) {
-				sb.append(" asc ");
-			} else {
-				sb.append(" desc ");
+				case "itemType":
+					sb.append(dbRef).append(".type.type ");
+					appendAsc(sb, asc);
+					break;
+				case "marks":
+					sb.append("marks");
+					appendAsc(sb, asc);
+					break;
+				case "rating":
+					sb.append("rating");
+					appendAsc(sb, asc);
+					sb.append(" nulls last");
+					break;
+				case "keywords":
+				case "coverage":
+				case "additionalInformations":
+					sb.append("lower(").append(dbRef).append(".").append(sortKey).append(")");
+					appendAsc(sb, asc);
+					sb.append(" nulls last");
+					break;	
+				default:
+					sb.append(dbRef).append(".").append(sortKey);
+					appendAsc(sb, asc);
+					sb.append(" nulls last");
+					break;
 			}
 		} else {
 			sb.append(" order by item.key asc ");
 		}
 	}
+	
+	private final StringBuilder appendAsc(StringBuilder sb, boolean asc) {
+		if(asc) {
+			sb.append(" asc");
+		} else {
+			sb.append(" desc");
+		}
+		return sb;
+	}
 }

src/main/java/org/olat/modules/qpool/ui/metadata/GeneralMetadataEditController.java

@@ -197,9 +197,21 @@ public class GeneralMetadataEditController extends FormBasicController {
 		if(item instanceof QuestionItemImpl) {
 			QuestionItemImpl itemImpl = (QuestionItemImpl)item;
 			itemImpl.setTitle(titleEl.getValue());
-			itemImpl.setKeywords(keywordsEl.getValue());
-			itemImpl.setCoverage(coverageEl.getValue());
-			itemImpl.setAdditionalInformations(addInfosEl.getValue());
+			if(StringHelper.containsNonWhitespace(keywordsEl.getValue())) {
+				itemImpl.setKeywords(keywordsEl.getValue());
+			} else {
+				itemImpl.setKeywords("");
+			}
+			if(StringHelper.containsNonWhitespace(coverageEl.getValue())) {
+				itemImpl.setCoverage(coverageEl.getValue());
+			} else {
+				itemImpl.setCoverage("");
+			}
+			if(StringHelper.containsNonWhitespace(addInfosEl.getValue())) {
+				itemImpl.setAdditionalInformations(addInfosEl.getValue());
+			} else {
+				itemImpl.setAdditionalInformations(null);
+			}
 			itemImpl.setLanguage(languageEl.getValue());
 			if(selectedTaxonomicPath != null) {
 				itemImpl.setTaxonomyLevel(selectedTaxonomicPath);

src/main/java/org/olat/upgrade/_spring/databaseUpgradeContext.xml

@@ -124,6 +124,10 @@
 					<constructor-arg index="0" value="OLAT_11.1.0" />
 					<property name="alterDbStatements" value="alter_11_x_0_to_11_1_0.sql" />
 				</bean>
+				<bean id="database_upgrade_11_1_2" class="org.olat.upgrade.DatabaseUpgrade">
+					<constructor-arg index="0" value="OLAT_11.1.2" />
+					<property name="alterDbStatements" value="alter_11_1_1_to_11_1_2.sql" />
+				</bean>
 			</list>
 		</property>
 	</bean>

src/main/resources/database/mysql/alter_11_1_1_to_11_1_2.sql

+update o_qp_item set q_keywords=null where q_keywords='';
+update o_qp_item set q_coverage=null where q_coverage='';
\ No newline at end of file

src/main/resources/database/postgresql/alter_11_1_1_to_11_1_2.sql

+update o_qp_item set q_keywords=null where q_keywords='';
+update o_qp_item set q_coverage=null where q_coverage='';
\ No newline at end of file