The table provides NDB
dictionary information
about columns of NDB
tables.
dictionary_columns
has the columns listed
here (with brief descriptions):
table_id
ID of the table containing the column
column_id
The column's unique ID
name
Name of the column
column_type
Data type of the column from the NDB API; see Column::Type, for possible values
default_value
The column's default value, if any
nullable
Either of
NULL
orNOT NULL
array_type
The column's internal attribute storage format; one of
FIXED
,SHORT_VAR
, orMEDIUM_VAR
; for more information, see Column::ArrayType, in the NDB API documentationstorage_type
Type of storage used by the table; either of
MEMORY
orDISK
primary_key
1
if this is a primary key column, otherwise0
partition_key
1
if this is a partitioning key column, otherwise0
dynamic
1
if the column is dynamic, otherwise0
auto_inc
1
if this is anAUTO_INCREMENT
column, otherwise0
You can obtain information about all of the columns in a given
table by joining dictionary_columns
with the
dictionary_tables
table, like
this:
SELECT dc.*
FROM dictionary_columns dc
JOIN dictionary_tables dt
ON dc.table_id=dt.table_id
WHERE dt.table_name='t1'
AND dt.database_name='mydb';
Blob columns are not shown in this table. This is a known issue.