SELECT * FROM MY_TABLE;
CLOUMN_NAME
1st
2nd
3rd
Am getting the output when I run this query.
I need to have a default value for 'Please Select' as first row always even column holds the empty or null value of the result set.
Exptected Result
CLOUMN_NAME
Please Select
1st
2nd
3rd
Thanks in advance.
Try to use union all as below
SELECT 'Please Select' as CLOUMN_NAME
union all
SELECT cast(CLOUMN_NAME as varchar) FROM MY_TABLE;
I'm not sure what type is CLOUMN_NAME but should be string type because in first query we return this type.
select 'please select' col_name
union all
select col_name::text FROM MY_TABLE;
Edit : as per this comment
In your case you need to use order by in second select statement
select 'please select' col_name
union all
(select col_name::text FROM MY_TABLE order by 1)
you need to convert column in that table(MY_TABLE) to text if that column is not a Text,varchar
If you want a stable sort you need some kind of criteria to distinguish the "first" row from the "real" ones:
select column_name
from (
select 'please select' as column_name, 0 as sort_order
union all
select column_name, 1 as sort_order
FROM MY_TABLE
) t
order by sort_order;
Note that the sort order for the actual data is undefined in this case because all rows from the table get the same "sort_order" value. If you e.g. want the real rows to be sorted alphabetically, you can add the display column to the order by: `order by sort_order, column_name.
The above assumes that my_table.column_name is a character data type. If it is not, you need some type casting.