SELECT DISTINCT field1, field2, field3, ...... FROM table
SELECT DISTINCT field1, * from table
You're looking for a group by:
select * from table group by field1
Which can occasionally be written with a distinct on statement:
select distinct on field1 * from table
On most platforms, however, neither of the above will work because the behavior on the other columns is unspecified. (The first works in MySQL, if that's what you're using.)
You could fetch the distinct fields and stick to picking a single arbitrary row each time.
On some platforms (e.g. PostgreSQL, Oracle, T-SQL) this can be done directly using window functions:
select * from ( select *, row_number() over (partition by field1 order by field2) as row_number from table ) as rows where row_number = 1
On others (MySQL, SQLite), you'll need to write subqueries that will make you join the entire table with itself (example), so not recommended.