COLUMN_ADD(dyncol_blob, column_nr, value [as type], [column_nr, value [as type]]...)
COLUMN_ADD(dyncol_blob, column_name, value [as type], [column_name, value [as type]]...)
Adds or updates dynamic columns.
dyncol_blob
must be either a valid dynamic columns blob (for example, COLUMN_CREATE
returns such blob), or an empty string.
column_name
specifies the name of the column to be added. If dyncol_blob
already has a column with this name, it will be overwritten.
value
specifies the new value for the column. Passing a NULL value will cause the column to be deleted.
as type
is optional. See #datatypes section for a discussion about types.
The return value is a dynamic column blob after the modifications.
UPDATE t1 SET dyncol_blob=COLUMN_ADD(dyncol_blob, "column_name", "value") WHERE id=1;
Note: COLUMN_ADD()
is a regular function (just like CONCAT()), hence, in order to update the value in the table you have to use the UPDATE ... SET dynamic_col=COLUMN_ADD(dynamic_col, ....)
pattern.
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