Partitioning of table in mysql for MYISAM eninge based on year - php

Question

I am trying to partition the table based on the year range.
but i'm getting the following error "#1503 - A PRIMARY KEY must include all columns in the table's partitioning function".
Following is my query
CREATE TABLE IF NOT EXISTS `t2123` (
`j_id` int(11) NOT NULL AUTO_INCREMENT,
`u_id` int(11) NOT NULL,
`w_id` int(5) NOT NULL,
`p_id` int(5) NOT NULL,
`s_p_id` int(5) NOT NULL,
`p_t` tinyint(3) unsigned NOT NULL,
`a_n` int(5) NOT NULL,
`type` enum('GP','NGP','PGP','PAGP') NOT NULL,
`p_p` int(11) NOT NULL,
`s_p` int(11) NOT NULL,
`p_c` float NOT NULL,
`s_c` float NOT NULL,
`s_p_p_c` float NOT NULL DEFAULT '0',
`g_d` date NOT NULL,
`datetimes` TIMESTAMP NOT NULL DEFAULT '0000-00-00 00:00:00',
`c_c` double DEFAULT '0',
`c_m` double DEFAULT '0',
`c_y` double DEFAULT '0',
`c_k` double DEFAULT '0' ,
`c_total` double DEFAULT '0' ,
`p_a` float DEFAULT '0',
PRIMARY KEY (`j_id`),
UNIQUE KEY(j_id, g_d),
KEY `u_id` (`u_id`),
KEY `w_id` (`w_id`),
KEY `p_id` (`p_id`),
KEY `s_p_id` (`s_p_id`),
KEY `a_n` (`a_n`),
KEY `g_d` (`g_d`)
) engine=myisam PARTITION BY RANGE (j_id + year(g_d)) (
PARTITION t2_2012 VALUES LESS THAN (2012),
PARTITION t2_2013 VALUES LESS THAN (2013)
);
Please suggest me how can I create the partition?

Answer 1

As the error message advises:
A PRIMARY KEY must include all columns in the table's partitioning function
Your partitioning function refers to j_id and g_d while your primary key only covers j_id.
By the way, your UNIQUE constraint is useless (UNIQUE KEY(j_id, g_d)) because j_id is already unique by definition (it is primary key).
In fact you probably want your primary key on (j_id, g_d)