We can append a string or data to an existing data of a field by using concat function of MySQL. Here we are not updating or replacing an existing data with new one, we are just adding the string at the end of the field data.
For example we want to add site signature at the end of the comments posted by users. Here each user posts are different so we can't apply any update command so we will use concat to add the site signature to the each post kept inside a record – field in our update command.
Here is the syntax
concat(field_name,"string to add")
Now let us see how it is used in a MySQL table query.
update photo_img set dtl=concat(dtl,'site_data to add') where gal_id='22'