add attribute_blob to the Attribute table

Author: Thinh Nguyen

element_event/trial.py

@@ -61,10 +61,11 @@ class Block(dj.Imported):
     class Attribute(dj.Part):
         definition = """  # Additional block attributes to fully describe a block
         -> master
-        attribute_name    : varchar(16)
+        attribute_name    : varchar(32)
         ---
-        attribute_value   : varchar(2000)
-        """
+        attribute_value='': varchar(2000)
+        attribute_blob=null: longblob
+        """   
 
 
 @schema
@@ -90,10 +91,11 @@ class Trial(dj.Imported):
     class Attribute(dj.Part):
         definition = """  # Additional trial attributes to fully describe a trial
         -> master
-        attribute_name  : varchar(16)
+        attribute_name    : varchar(32)
         ---
-        attribute_value : varchar(2000)
-        """
+        attribute_value='': varchar(2000)
+        attribute_blob=null: longblob
+        """   
 
 
 @schema