mysql replace text in a table

How i replace text in a table , me using mysql

without any edit into records from website control panel i wish to run a query so all domains like without www will include www.

or

wish to replace a word from a table from expertweb to expertwebworld using one query .

Here is the solution


update table_name set field = replace(field, 'foo', 'bar') where instr(field, 'foo') > 0;

Here field is the column name. it will do this without wasting time to edit the records from admin.