Large objects in MySQL are columns with following data types: blob, mediumblob, longblob, text, mediumtext, and longtext.
The query below lists all tables that contain columns with LOB data types.
Query
select tab.table_name,
count(*) as columns
from information_schema.tables as tab
inner join information_schema.columns as col
on col.table_schema = tab.table_schema
and col.table_name = tab.table_name
and col.data_type in ('blob', 'mediumblob', 'longblob',
'text', 'mediumtext', 'longtext')
where tab.table_schema = 'your database name'
and tab.table_type = 'BASE TABLE'
group by tab.table_name
order by tab.table_name;
Columns
- table_name - name of the table
- columns - number of LOB columns in a table
Rows
- One row: represents one table
- Scope of rows: all tables containing columns with LOB data types in the current database (schema)
- Ordered by: table name
Sample results
List of tables with LOB columns in the Sakila database (schema):