Using rownum and order-by

If you try to use rownum and order-by in a select statement, maybe the result will not match with your expectation. It is because the order-by is one of the last operation in the queue.

Using rownum function

The query:
SELECT ROWNUM,
       T.DOMA_KY,

       T.SHORT_DESCRIPTION_LB

  FROM T_DOMAIN T
 WHERE T.ACRONYM_CD = 'PLCY'
 ORDER BY T.DOMA_KY

	ROWNUM	DOMA_KY	SHORT_DESCRIPTION_LB
1	6	261	P1-Jobs, Growth and Investment
2	2	262	P2-Digital Single Market
3	4	263	P3-Energy Union and Climate
4	8	264	P4-Internal Market
5	3	265	P5-Economic and Monetary Union
6	10	266	P6-EU-US Free Trade
7	7	267	P7-Justice and Fundamental Rights
8	9	268	P8-Migration
9	5	269	P9-EU as Global Actor
10	1	270	P10-Democratic Change

Using row_number() function

The query:
SELECT ROW_NUMBER() OVER (ORDER BY T.DOMA_KY) ROW_NUMBER,
       T.DOMA_KY,
       T.SHORT_DESCRIPTION_LB,
       T.ROWID
  FROM T_DOMAIN T
 WHERE T.ACRONYM_CD = 'PLCY'
 ORDER BY T.DOMA_KY

	ROW_NUMBER	DOMA_KY	SHORT_DESCRIPTION_LB
1	1	261	P1-Jobs, Growth and Investment
2	2	262	P2-Digital Single Market
3	3	263	P3-Energy Union and Climate
4	4	264	P4-Internal Market
5	5	265	P5-Economic and Monetary Union
6	6	266	P6-EU-US Free Trade
7	7	267	P7-Justice and Fundamental Rights
8	8	268	P8-Migration
9	9	269	P9-EU as Global Actor
10	10	270	P10-Democratic Change