Different types accepted by CAST() and COLUMN_CREATE()

[Philip Stoev]

The dynamic columns documentation at

http://kb.askmonty.org/v/dynamic-columns

provides a list of data types GET_COLUMN() accepts, as well as the note "Type here can be one of the same ones that you would use in CAST or CONVERT:". However, in practice, the allowed types for CAST and for GET_COLUMN are different and are different from what is specified in the dynamic columns manual.

GET_COLUMN() accepts DOUBLE while CAST does not
GET_COLUMN() does not accept SIGNED, UNSIGNED, BINARY and CHAR(N)

[Michael Widenius (monty)]

select cast(1 as double) works in 5.3-mwl tree; It was added as part of this worklog.
select column_get(column_create(1, 2), 1 as signed) worked for me. All the other versions should also work as the parsing code in sql_yacc.yy is identical for CAST and COLUMN_GET().
COLUMN_CREATE is still 'different' but is scheduled to be fixed.

I tested the following commands and they worked correctly in 5.3-mwl:

column_get(column_create(1, 2), 1 as signed)
select column_get(column_create(1, 2), 1 as unsigned)
select column_get(column_create(1, 2), 1 as CHAR(5))
select column_get(column_create(1, 2), 1 as BINARY(5));
select column_get(column_create(1, 2), 1 as BINARY)`

I have now updated the documentation about this.

[Philip Stoev (pstoev-askmonty)]

If there is a part that is "scheduled to be fixed", then this bug remains on the table.

[Elena Stepanova (elenst)]

Also filed in JIRA as MDEV-196