How to select only 1 row from oracle sql?

I want to use oracle syntax to select only 1 row from table DUAL. For example, I want to execute this query:

SELECT user FROM DUAL 

...and it'd have, like, 40 records. But I need only one record. ...AND, I want to make it happen without a WHERE clause.

I need something in the table_name field such as:

SELECT FirstRow(user) FROM DUAL 

13 Answers

You use ROWNUM.

ie.

SELECT user FROM Dual WHERE ROWNUM = 1 

This syntax is available in Oracle 12c:

select * from some_table fetch first 1 row only; select * from some_table fetch first 1 rows only; select * from some_table fetch first 10 row only; select * from some_table fetch first 10 rows only; 

^^I just wanted to demonstrate that either row or rows (plural) can be used regardless of the plurality of the desired number of rows.)

I found this "solution" hidden in one of the comments. Since I was looking it up for a while, I'd like to highlight it a bit (can't yet comment or do such stuff...), so this is what I used:

SELECT * FROM (SELECT [Column] FROM [Table] ORDER BY [Date] DESC) WHERE ROWNUM = 1 

This will print me the desired [Column] entry from the newest entry in the table, assuming that [Date] is always inserted via SYSDATE.

we have 3 choices to get the first row in Oracle DB table.

1) select * from table_name where rownum= 1 is the best way

2) select * from table_name where id = ( select min(id) from table_name)

3)

select * from (select * from table_name order by id) where rownum = 1 

👌 The answer is:

You should use nested query as:

SELECT * FROM ANY_TABLE_X WHERE ANY_COLUMN_X = (SELECT MAX(ANY_COLUMN_X) FROM ANY_TABLE_X) 

=> In PL/SQL "ROWNUM = 1" is NOT equal to "TOP 1" of TSQL.

So you can't use a query like this: "select * from any_table_x where rownum=1 order by any_column_x;" Because oracle gets first row then applies order by clause.

As far as I know, the dual table in Oracle is a special table with just one row. So, this would suffice:

SELECT user FROM dual 

There is no limit 1 condition (thats MySQL / PostgresSQL) in Oracle, you need to specify where rownum = 1.

"FirstRow" Is a restriction and therefor it's place in the where clause not in the select clause. And it's called rownum

select * from dual where rownum = 1; 

If you want to get back only the first row of a sorted result with the least subqueries, try this:

select * from ( select a.* , row_number() over ( order by sysdate_col desc ) as row_num from table_name a ) where row_num = 1; 

If any row would do, try:

select max(user) from table; 

No where clause.

select name, price from ( select name, price, row_number() over (order by price) r from items ) where r between 1 and 5; 

select a.user from (select user from users order by user) a where rownum = 1

will perform the best, another option is:

select a.user from ( select user, row_number() over (order by user) user_rank, row_number() over (partition by dept order by user) user_dept_rank from users ) a where a.user_rank = 1 or user_dept_rank = 2 

in scenarios where you want different subsets, but I guess you could also use RANK() But, I also like row_number() over(...) since no grouping is required.

More flexible than select max() is:

select distinct first_row(column_x) over (order by column_y,column_z,...) from Table_A