Let's start with some terminology. The words we use matter!
You have a
Database, which contains multiple
Tables.
Each Table contains one or more
Columns, each of which is of a specific Data Type.
Each Table contains any number of
Rows.
To add Rows into a Table, you INSERT into them.
To read data from table(s), you SELECT the data from them.
To remove Rows from a Table, you DELETE those Rows.
To change values in the Columns within a Row, you UPDATE them.
Everything is SQL is Set-based. You identify a set of Rows based on some criteria and then perform some "operation" on them (and yes, "selecting" is an "operation" as well).
So ...
What you
want to do is to
update the value in the Column
variable_value (to 754) in the Row
identified by variable_id = 1 in the Table
my_variables, which looks a lot like this:
update my_variables
set variable_value = 754
where variable_id = 1 ;
Regards,
Phill Ward.