diff --git a/lib/core/agent.py b/lib/core/agent.py
index 9fa48e8aa..1a34f0299 100644
--- a/lib/core/agent.py
+++ b/lib/core/agent.py
@@ -385,7 +385,8 @@ class Agent:
         elif fieldsNoSelect:
             fieldsToCastStr = fieldsNoSelect
 
-        if re.search("\A\w+\(.*\)", fieldsToCastStr, re.I): # Function
+        # Function
+        if re.search("\A\w+\(.*\)", fieldsToCastStr, re.I) or fieldsSelectCase:
             fieldsToCastList = [fieldsToCastStr]
         else:
             fieldsToCastList = fieldsToCastStr.replace(", ", ",")
@@ -700,10 +701,15 @@ class Agent:
         @rtype: C{str}
         """
 
+        caseExpression = expression
+
         if Backend.getIdentifiedDbms() is not None and hasattr(queries[Backend.getIdentifiedDbms()], "case"):
-            return queries[Backend.getIdentifiedDbms()].case.query % expression
-        else:
-            return expression
+            caseExpression = queries[Backend.getIdentifiedDbms()].case.query % expression
+
+            if Backend.getIdentifiedDbms() in FROM_TABLE and not caseExpression.upper().endswith(FROM_TABLE[Backend.getIdentifiedDbms()]):
+                caseExpression += FROM_TABLE[Backend.getIdentifiedDbms()]
+
+        return caseExpression
 
     def addPayloadDelimiters(self, inpStr):
         """
diff --git a/xml/queries.xml b/xml/queries.xml
index a25a43e8a..d1bc05b1b 100644
--- a/xml/queries.xml
+++ b/xml/queries.xml
@@ -225,7 +225,7 @@
         <comment query="--"/>
         <timedelay query="BEGIN DBMS_LOCK.SLEEP(%d); END" query2="EXEC DBMS_LOCK.SLEEP(%d.00)" query3="EXEC USER_LOCK.SLEEP(%d.00)"/>
         <substring query="SUBSTR((%s), %d, %d)"/>
-        <case query="SELECT (CASE WHEN (%s) THEN 1 ELSE 0 END) FROM DUAL"/>
+        <case query="SELECT (CASE WHEN (%s) THEN 1 ELSE 0 END)"/>
         <inference query="ASCII(SUBSTR((%s), %d, 1)) > %d"/>
         <banner query="SELECT banner FROM v$version WHERE ROWNUM=1"/>
         <current_user query="SELECT USER FROM DUAL"/>
@@ -386,7 +386,7 @@
         <count query="COUNT(%s)"/>
         <timedelay query="SELECT COUNT(*) FROM RDB$DATABASE AS T1, RDB$FIELDS AS T2, RDB$FUNCTIONS AS T3, RDB$TYPES AS T4, RDB$FORMATS AS T5, RDB$COLLATIONS AS T6"/>
         <substring query="SUBSTRING((%s) FROM %d FOR %d)"/>
-        <case query="SELECT IIF(%s,1,0) FROM RDB$DATABASE"/>
+        <case query="SELECT IIF(%s,1,0)"/>
         <banner query="SELECT RDB$GET_CONTEXT('SYSTEM', 'ENGINE_VERSION') FROM RDB$DATABASE" dbms_version="&gt;=2.1"/>
         <current_user query="SELECT CURRENT_USER FROM RDB$DATABASE"/>
         <current_db query="SELECT RDB$GET_CONTEXT('SYSTEM', 'DB_NAME') FROM RDB$DATABASE"/>