PHP Developer Channel :: 討論園地

CREATE TABLE `definedatabase1_content` (
`define1_id` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY ,
`define1_title` VARCHAR( 50 ) NOT NULL ,
`define1_attributenum` INT( 20 ) NOT NULL ,
`define1_expertnum` INT( 20 ) NOT NULL ,
`define1_questionnaireeach` BIGINT( 255 ) NOT NULL ,
`define1_purposaltext` VARCHAR( 500 ) NOT NULL ,
INDEX ( `define1_title` , `define1_attributenum` , `define1_expertnum` , `define1_questionnaireeach` , `define1_purposaltext` )
) ENGINE = MYISAM COMMENT = 'definedatabase1儲存內容資料表'

MySQL 傳回： 說明文件
#1170 - BLOB/TEXT column 'define1_purposaltext' used in key specification without a key length

請問我是哪裡出了錯呢?
拜推各位高手指點一下!!

Yours,
Michael (Taiwan)