Data_alias liquibase MS SQL problems fixed

.liquibase/Data_alias/basic/2019.1.4/Ticketmanagement/create_Ticket_table.xml

 <?xml version="1.1" encoding="UTF-8" standalone="no"?>
 <databaseChangeLog xmlns="http://www.liquibase.org/xml/ns/dbchangelog" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.6.xsd">
     <changeSet author="j.hoermann" id="15176b40-4b5e-48a9-8dfc-4540b01595c8">
+        <preConditions onFail="CONTINUE">
+            <not>
+                <tableExists tableName="TICKET"/>
+            </not>
+        </preConditions>
+        
         <createTable tableName="TICKET">
             <column name="TICKETID" type="CHAR(36)">
                 <constraints primaryKey="true" primaryKeyName="PK_TICKET_TICKETID"/>
@@ -12,6 +18,13 @@
             <column name="TICKETTYPE" type="VARCHAR(36)"/>
         </createTable>
         
+        <sql dbms="mssql">
+            DECLARE @ConstraintName nvarchar(200)
+            SELECT @ConstraintName = CONSTRAINT_NAME FROM INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE WHERE TABLE_NAME = 'TASK' AND COLUMN_NAME = 'CODE'
+            IF @ConstraintName IS NOT NULL
+                EXEC('ALTER TABLE TASK DROP CONSTRAINT ' + @ConstraintName)
+        </sql>
+        <dropNotNullConstraint tableName="TASK" columnName="CODE" columnDataType="INTEGER"/>
         <dropColumn tableName="TASK" columnName="CODE"/>
     </changeSet>
 </databaseChangeLog>
\ No newline at end of file

.liquibase/Data_alias/basic/2019.1.4/alter_activityLink.xml

@@ -9,13 +9,15 @@
         </sql>
     </changeSet>
     
-    <changeSet author="j.hoermann" id="9a86323f-a299-42a5-937a-f5e37d0db507">
-        <preConditions onFail="CONTINUE">
-            <not>
-                <dbms type="derby" />
-            </not>
-        </preConditions>
-
+    <changeSet dbms="!derby,!mssql" author="j.hoermann" id="9a86323f-a299-42a5-937a-f5e37d0db507">
         <modifyDataType tableName="ACTIVITYLINK" columnName="ACTIVITY_ID" newDataType="CHAR(36)"/>
     </changeSet>
+    
+    <changeSet dbms="mssql" author="s.listl" id="e8961eb9-80af-4a60-98cb-3cd843f2424a">
+        <dropIndex tableName="ACTIVITYLINK" indexName="IDX_ACTIVITYLINK_ACTIVITY_ID"/>
+        <modifyDataType tableName="ACTIVITYLINK" columnName="ACTIVITY_ID" newDataType="CHAR(36)"/>
+        <createIndex indexName="IDX_ACTIVITYLINK_ACTIVITY_ID" tableName="ACTIVITYLINK">
+            <column name="ACTIVITY_ID" />
+        </createIndex>
+    </changeSet>
 </databaseChangeLog>
\ No newline at end of file

.liquibase/Data_alias/basic/2020.0.2/Memberroles/alter_member.xml

@@ -2,6 +2,11 @@
 <databaseChangeLog xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
                    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.6.xsd">
     <changeSet author="s.pongratz" id="28627941-6c9b-46e8-922a-b4660b33723c">
+        <preConditions onFail="CONTINUE">
+            <columnExists tableName="OBJECTMEMBER" columnName="DECIDER"/>
+        </preConditions>
+        <dropNotNullConstraint tableName="OBJECTMEMBER" columnName="DECIDER" columnDataType="TINYINT"/>
+        <dropDefaultValue tableName="OBJECTMEMBER" columnName="DECIDER"/>
         <dropColumn tableName="OBJECTMEMBER" columnName="DECIDER"/>
     </changeSet>
 </databaseChangeLog>