Elena Stepanova added a comment - 2015-08-30 18:29 wzrdtales , What do you mean by "anymore" and "now"? In which version did you see it work?

Tobias Gurtzick added a comment - 2015-08-31 00:02 Well I don't know in which version this has worked. But there are posts indicating that this was possible and has worked: http://dba.stackexchange.com/questions/91620/modify-a-value-inside-of-a-nested-dynamic-column https://mariadb.atlassian.net/browse/MDEV-7606?jql=text%20~%20%22dynamic%20columns%22 This suggests that it was possible, I wonder if it is possible in any way to modify a nested column right now?

Elena Stepanova added a comment - 2015-09-01 16:13 I don't think AS BLOB ever worked. Data types allowed in COLUMN_GET are explicitly listed in documentation , it's unlikely they had ever been wider. However, I will assign it to sanja , who is an expert in dynamic columns, to confirm. I can guess that serg in MDEV-7606 just gave an example of what should be simplified, without paying attention to specific data types; can't say anything about the answer in the stackoverflow article, maybe the person just pasted a wrong query (as they say, there had been a lot of trial/fails). Using nested columns is of course still possible, as documented on the same KB page , but you need to use CHAR , not BLOB . MariaDB [test]> create table t1 (dcol blob); Query OK, 0 rows affected (0.06 sec)   MariaDB [test]> insert into t1 values ( column_create( 'level1' , column_create( 'value' , 1) ) ); Query OK, 1 row affected (0.05 sec)   MariaDB [test]> SELECT COLUMN_GET(COLUMN_GET(dcol, 'level1' as CHAR ), 'value' as INT ) FROM t1; + ----------------------------------------------------------------+ | COLUMN_GET(COLUMN_GET(dcol, 'level1' as CHAR ), 'value' as INT ) | + ----------------------------------------------------------------+ | 1 | + ----------------------------------------------------------------+ 1 row in set (0.00 sec)

Oleksandr Byelkin added a comment - 2015-09-03 11:18 BLOB is a field type and is not related to expressions. AS CHAR should work (it will be charset binary). Do you really faced some limitation of string expression?

Oleksandr Byelkin added a comment - 2015-09-03 11:27 To make it even more clear BLOB give no advantage over CHAR when it is in expression. There both are strings.