How to update text field data of mysql database

How can I update data of the mysql database text field type? The content field of the following statement is of the text type. I use UPDATEtableSETtitle = 'dhl333', content = CONCAT (content, '20140901 ') WHEREarticle_id = 15 & how can I update the data of the mysql database text field type?
The content field of the following statement is of the text type,

I use UPDATE table SET title = 'dhl333', content = CONCAT (content, '20140901') WHERE article_id = 15

I found that the content of the content field is constantly superimposed, rather than replaced. I want to replace the content.

------ Solution --------------------
CONCAT is a concatenation string.

Or simply = '000000' to meet the requirements.