ALTER TABLE - Rename a column

The valid syntax is close to your second try, but you need to escape the column names with backticks not with single quotes:

ALTER TABLE `blog` CHANGE COLUMN `read-more` `read_more` VARCHAR(255) NOT NULL;

ALTER TABLE `blog` CHANGE  `read-more` `read_more` VARCHAR(255) NOT NULL;

Above mentioned query is correct and there is no need to use "column" keyword and quotes around table and column name if you are using mysql database:

ALTER TABLE blog CHANGE read-more read_more VARCHAR(255) NOT NULL;

Here's what worked for me:

ALTER TABLE vm_list CHANGE `vm_notes]` vm_notes VARCHAR(255); 

Query OK, 0 rows affected (0.01 sec) 
Records: 0  Duplicates: 0  Warnings: 0

Yes, I somehow got a column named "vm_notes]" in there.