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|
--
-- SELECT_DISTINCT
--
--
-- awk '{print $3;}' onek.data | sort -n | uniq
--
SELECT DISTINCT two FROM tmp ORDER BY 1;
two
-----
0
1
(2 rows)
--
-- awk '{print $5;}' onek.data | sort -n | uniq
--
SELECT DISTINCT ten FROM tmp ORDER BY 1;
ten
-----
0
1
2
3
4
5
6
7
8
9
(10 rows)
--
-- awk '{print $16;}' onek.data | sort -d | uniq
--
SELECT DISTINCT string4 FROM tmp ORDER BY 1;
string4
---------
AAAAxx
HHHHxx
OOOOxx
VVVVxx
(4 rows)
--
-- awk '{print $3,$16,$5;}' onek.data | sort -d | uniq |
-- sort +0n -1 +1d -2 +2n -3
--
SELECT DISTINCT two, string4, ten
FROM tmp
ORDER BY two using <, string4 using <, ten using <;
two | string4 | ten
-----+---------+-----
0 | AAAAxx | 0
0 | AAAAxx | 2
0 | AAAAxx | 4
0 | AAAAxx | 6
0 | AAAAxx | 8
0 | HHHHxx | 0
0 | HHHHxx | 2
0 | HHHHxx | 4
0 | HHHHxx | 6
0 | HHHHxx | 8
0 | OOOOxx | 0
0 | OOOOxx | 2
0 | OOOOxx | 4
0 | OOOOxx | 6
0 | OOOOxx | 8
0 | VVVVxx | 0
0 | VVVVxx | 2
0 | VVVVxx | 4
0 | VVVVxx | 6
0 | VVVVxx | 8
1 | AAAAxx | 1
1 | AAAAxx | 3
1 | AAAAxx | 5
1 | AAAAxx | 7
1 | AAAAxx | 9
1 | HHHHxx | 1
1 | HHHHxx | 3
1 | HHHHxx | 5
1 | HHHHxx | 7
1 | HHHHxx | 9
1 | OOOOxx | 1
1 | OOOOxx | 3
1 | OOOOxx | 5
1 | OOOOxx | 7
1 | OOOOxx | 9
1 | VVVVxx | 1
1 | VVVVxx | 3
1 | VVVVxx | 5
1 | VVVVxx | 7
1 | VVVVxx | 9
(40 rows)
--
-- awk '{print $2;}' person.data |
-- awk '{if(NF!=1){print $2;}else{print;}}' - emp.data |
-- awk '{if(NF!=1){print $2;}else{print;}}' - student.data |
-- awk 'BEGIN{FS=" ";}{if(NF!=1){print $5;}else{print;}}' - stud_emp.data |
-- sort -n -r | uniq
--
SELECT DISTINCT p.age FROM person* p ORDER BY age using >;
age
-----
98
88
78
68
60
58
50
48
40
38
34
30
28
25
24
23
20
19
18
8
(20 rows)
--
-- Also, some tests of IS DISTINCT FROM, which doesn't quite deserve its
-- very own regression file.
--
CREATE TEMP TABLE disttable (f1 integer);
INSERT INTO DISTTABLE VALUES(1);
INSERT INTO DISTTABLE VALUES(2);
INSERT INTO DISTTABLE VALUES(3);
INSERT INTO DISTTABLE VALUES(NULL);
-- basic cases
SELECT f1, f1 IS DISTINCT FROM 2 as "not 2" FROM disttable;
f1 | not 2
----+-------
1 | t
2 | f
3 | t
| t
(4 rows)
SELECT f1, f1 IS DISTINCT FROM NULL as "not null" FROM disttable;
f1 | not null
----+----------
1 | t
2 | t
3 | t
| f
(4 rows)
SELECT f1, f1 IS DISTINCT FROM f1 as "false" FROM disttable;
f1 | false
----+-------
1 | f
2 | f
3 | f
| f
(4 rows)
SELECT f1, f1 IS DISTINCT FROM f1+1 as "not null" FROM disttable;
f1 | not null
----+----------
1 | t
2 | t
3 | t
| f
(4 rows)
-- check that optimizer constant-folds it properly
SELECT 1 IS DISTINCT FROM 2 as "yes";
yes
-----
t
(1 row)
SELECT 2 IS DISTINCT FROM 2 as "no";
no
----
f
(1 row)
SELECT 2 IS DISTINCT FROM null as "yes";
yes
-----
t
(1 row)
SELECT null IS DISTINCT FROM null as "no";
no
----
f
(1 row)
-- negated form
SELECT 1 IS NOT DISTINCT FROM 2 as "no";
no
----
f
(1 row)
SELECT 2 IS NOT DISTINCT FROM 2 as "yes";
yes
-----
t
(1 row)
SELECT 2 IS NOT DISTINCT FROM null as "no";
no
----
f
(1 row)
SELECT null IS NOT DISTINCT FROM null as "yes";
yes
-----
t
(1 row)
|
