I've been attempting to do this for quite sometime.
I have a program which periodically writes rows to a table.
ID Date Text Number
The Date column is in format yyyy-mm-dd hh:mm:ss ("2013-08-03 06:26:27")
The script which reads the data matches it to another set of data with the date in the same format except that the seconds are exactly 0.
I need to change the Date data column in (Table 1) so that the seconds column is exactly zero. Currently it is just random values.
I have changed it on script level so that it writes the data to the MYSQL table so that the seconds is 0. However I have a lot of existing data which I can not loose which does not have the seconds at 0.
This is just a matter of updating the corresponding column.
Depending on ... hum ... your mood (?) you might try:
update tbl set datetime_column = substr(datetime_column, 1, 16);
update tbl set datetime_column = date_format(datetime_column, '%Y-%m-%d %H:%i:00');
update tbl set datetime_column = datetime_column - second(datetime_column);