How to exclude certain rows from sql select - sql

Question

How do I exclude certain rows?
For example, I have the following table:
+------+------+------+
| Col1 | Col2 | Col3 |
+------+------+------+
| 1 | 1 | R |
| 1 | 2 | D |
| 2 | 3 | R |
| 2 | 4 | R |
| 3 | 5 | R |
| 4 | 6 | D |
+------+------+------+
I need to select only:
| 2 | 3 | R |
| 2 | 4 | R |
| 3 | 5 | R |
My select that does not work properly:
with t (c1,c2,c3) as(
select 1 , 1 , 'R' from dual union all
select 1 , 2 , 'D' from dual union all
select 2 , 3 , 'R' from dual union all
select 2 , 4 , 'R' from dual union all
select 3 , 5 , 'R' from dual union all
select 4 , 6 , 'D' from dual),
tt as (select t.*,count(*) over (partition by c1) cc from t ) select * from tt where cc=1 and c3='R';
Thanks in advance!

Answer 1

select * from table where col2 = 'R'
or if you want to exclude rows with D value just
select * from table where col2 != 'D'

Answer 2

It depends on your requirements but you can do in this way:
SELECT * FROM `table` WHERE col1 = 2 AND col3 = "R"
if you want to exclude just do it like WHERE col1 != 1
You ca also use IN clause also e.g.
SELECT column_name(s)
FROM table_name
WHERE column_name IN (value1, value2, ...);
This syntax is for MySql, but you can modify it as per your requirement or database you are using.

Answer 3

this will work :
select * from (select * from table_name) where rownum<=4
minus
select * from ( select * from table_name) where rownum<=2

Answer 4

My guess is that you want all rows for a col1 where no row for a col1 = D and at least 1 row for a col1 = R. # where [not] exists may do
DROP TABLE T;
CREATE TABLE T
(Col1 NUMBER, Col2 NUMBER, Col3 VARCHAR(1));
INSERT INTO T VALUES ( 1 , 1 , 'R');
INSERT INTO T VALUES ( 1 , 2 , 'D');
INSERT INTO T VALUES ( 2 , 3 , 'R');
INSERT INTO T VALUES ( 2 , 4 , 'R');
INSERT INTO T VALUES ( 3 , 5 , 'R');
INSERT INTO T VALUES ( 3 , 6 , 'D');
INSERT INTO T VALUES ( 4 , 5 , 'X');
INSERT INTO T VALUES ( 4 , 6 , 'Y');
INSERT INTO T VALUES ( 5 , 6 , 'X');
INSERT INTO T VALUES ( 5 , 5 , 'R');
INSERT INTO T VALUES ( 5 , 6 , 'Y');
SELECT *
FROM T
WHERE NOT EXISTS(SELECT 1 FROM T T1 WHERE T1.COL1 = T.COL1 AND COL3 = 'D') AND
EXISTS(SELECT 1 FROM T T1 WHERE T1.COL1 = T.COL1 AND COL3 = 'R');
Result
COL1 COL2 COL3
---------- ---------- ----
5 6 X
5 5 R
5 6 Y
2 3 R
2 4 R

Answer 5

use row_number() window function
with t (c1,c2,c3) as(
select 1 , 1 , 'R' from dual union all
select 1 , 2 , 'D' from dual union all
select 2 , 3 , 'R' from dual union all
select 2 , 4 , 'R' from dual union all
select 3 , 5 , 'R' from dual union all
select 4 , 6 , 'D' from dual
),
t1 as
(
select c1,c2,c3,row_number() over(order by c2) rn from t
) select * from t1 where t1.rn>=3 and t1.rn<=5
demo link
C1 C2 C3
2 3 R
2 4 R
3 5 R

Answer 6

You can try using correlated subquery
select * from tablename a
from
where exists (select 1 tablename b where a.col1=b.col1 having count(*)>1)

Answer 7

Based on what you have provided I can only surmise that the only requirement is for COL1 to be equal to 2 or 3 in that case all you have to do is (assuming that you actually have table);
SELECT * FROM <table_name>
WHERE col1 IN (2,3);
This will give you the desired output for the particular example provided in the question. If there is a selection requirement that goes beyond retrieving data where column 1 is either 2 or 3 than a more specific or precise answer can be provided.