I have already went through a number of questions and I couldn't find what I am exactly looking for.
Suppose I have a table as follows :
Col1 Col2 Col3
1,2,3 2,3,4,5,1 5,6
I need to get a result as follows using a select statement:
Col1 Col2 Col3
1,2,3 2,3,4,5,1 5,6
3 5 2
Note the added third column is the count of comma separated values.
Finding the count for a single column is simple, but this seems difficult if not impossible.
Thanks in advance.
select
col1,
regexp_count(col1, ',') + 1 as col1count,
col2,
regexp_count(col2, ',') + 1 as col2count,
col3,
regexp_count(col3, ',') + 1 as col3count
from t
FIDDLE
FIDDLE2
Per Count the number of elements in a comma separated string in Oracle an easy way to do this is to count the number of commas and then add 1
You just need the result unioned onto your original data. So, do that:
SQL> with the_data (col1, col2, col3) as (
2 select '1,2,3', '2,3,4,5,1', '5,6' from dual
3 )
4 select a.*
5 from the_data a
6 union all
7 select to_char(regexp_count(col1, ',') + 1)
8 , to_char(regexp_count(col2, ',') + 1)
9 , to_char(regexp_count(col3, ',') + 1)
10 from the_data;
COL1 COL2 COL
----- --------- ---
1,2,3 2,3,4,5,1 5,6
3 5 2
You need to convert the result to a character because you're unioning a character to a number, which Oracle will complain about.
It's worth noting that storing data in this manner violates the first normal form. This makes it far more difficult to manipulate and almost impossible to constrain to be correct. It's worth considering normalising your data model to make this, and other queries, simpler.
Finding the count for a single column is simple, but this seems difficult if not impossible.
So you don't to look for each column manually? You want it dynamically.
The design is actually flawed since it violates normalization. But if you are willing to stay with it, then you could do it in PL/SQL using REGEXP_COUNT.
Something like,
SQL> CREATE TABLE t AS
2 SELECT '1,2,3' Col1,
3 '2,3,4,5,1' Col2,
4 '5,6' Col3
5 FROM dual;
Table created.
SQL>
SQL> DECLARE
2 cnt NUMBER;
3 BEGIN
4 FOR i IN
5 (SELECT column_name FROM user_tab_columns WHERE table_name='T'
6 )
7 LOOP
8 EXECUTE IMMEDIATE 'select regexp_count('||i.column_name||', '','') + 1 from t' INTO cnt;
9 dbms_output.put_line(i.column_name||' has cnt ='||cnt);
10 END LOOP;
11 END;
12 /
COL3 has cnt =2
COL2 has cnt =5
COL1 has cnt =3
PL/SQL procedure successfully completed.
SQL>
Probably, there will be an XML solution in SQL itself, without using PL/SQL.
In SQL -
SQL> WITH DATA AS
2 ( SELECT '1,2,3' Col1, '2,3,4,5,1' Col2, '5,6' Col3 FROM dual
3 )
4 SELECT regexp_count(col1, ',') + 1 cnt1,
5 regexp_count(col2, ',') + 1 cnt2,
6 regexp_count(col3, ',') + 1 cnt3
7 FROM t;
CNT1 CNT2 CNT3
---------- ---------- ----------
3 5 2
SQL>
Related
More of a conceptual question. I have a query that calculates a sum of some values and checks it against a template value X, something like:
SELECT
SUM(...),
X,
SUM(...) - X AS delta
FROM
...
Now the query by itself works fine. The problem is that I need it to only display some results if the delta variable is non-zero, meaning there is a difference between the calculated sum and template X. If delta is zero, I need it to display nothing.
Is this possible to achieve in SQL? If yes, how would I go about it?
You have an aggregation query. Many, if not most, databases support column aliases in the having clause:
select . . .
from . . .
group by . . .
having delta <> 0;
For those that don't, it is probably simplest to repeat the expressions:
having sum( . . . ) <> X
You can also put the query into a CTE or subquery, and then use where on the subquery.
Oracle does not support column alias in the HAVING clause. so in oracle, You must have to repeat the aggregation in the HAVING clause.
See this:
SQL> SELECT MAX(COL1) AS RES,
2 COL2
3 FROM (select 1 as col1, 1 as col2 from dual
4 union all
5 select 10 as col1, 2 as col2 from dual)
6 GROUP BY COL2
7 HAVING RES > 5;
HAVING RES > 5
*
ERROR at line 7:
ORA-00904: "RES": invalid identifier
SQL> SELECT MAX(COL1) AS RES,
2 COL2
3 FROM (select 1 as col1, 1 as col2 from dual
4 union all
5 select 10 as col1, 2 as col2 from dual)
6 GROUP BY COL2
7 HAVING MAX(COL1) > 5;
RES COL2
---------- ----------
10 2
SQL>
I have a row of data and I want to turn this row into a column so I can use a cursor to run through the data one by one. I have tried to use
SELECT * FROM TABLE(PIVOT(TEMPROW))
but I get
'PIVOT' Invalid Identifier error.
I have also tried that same syntax but with
('select * from TEMPROW')
Everything I see using pivot is always using count or sum but I just want this one single row of all varchar2 to turn into a column.
My row would look something like this:
ABC | 123 | aaa | bbb | 111 | 222 |
And I need it to turn into this:
ABC
123
aaa
bbb
111
222
My code is similar to this:
BEGIN
OPEN C_1 FOR SELECT * FROM TABLE(PIVOT( 'SELECT * FROM TEMPROW'));
LOOP
FETCH C_1 INTO TEMPDATA;
EXIT WHEN C_2%NOTFOUND;
DBMS_OUTPUT.PUT_LINE(1);
END LOOP;
CLOSE C_1;
END;
You have to unpivot to convert whole row into 1 single column
select * from Table
UNPIVOT
(col for col in (
'ABC' , '123' , 'aaa' ,' bbb' , '111' , '222'
))
or use union but for that you need to add col names manually like
Select * from ( Select col1 from table
union
select col2 from table union...
Select coln from table)
sample output to show as below
One option for unpivoting would be numbering columns by decode() and cross join with the query containing the column numbers :
select decode(myId, 1, col1,
2, col2,
3, col3,
4, col4,
5, col5,
6, col6 ) as result_col
from temprow
cross join (select level AS myId FROM dual CONNECT BY level <= 6 );
or use a query with unpivot keyword by considering the common expression for the column ( namely col in this case ) must have same datatype as corresponding expression :
select result_col from
(
select col1, to_char(col2) as col2, col3, col4,
to_char(col5) as col5, to_char(col6) as col6
from temprow
)
unpivot (result_col for col in (col1,col2,col3,col4,col5,col6));
Demo
I just had this idea of how can i loop in sql?
For example
I have this column
PARAMETER_VALUE
E,C;S,C;I,X;G,T;S,J;S,F;C,S;
i want to store all value before (,) in a temp column also store all value after (;) into another column
then it wont stop until there is no more value after (;)
Expected Output for Example
COL1 E S I G S S C
COL2 C C X T J F S
etc . . .
You can get by using regexp_substr() window analytic function with connect by level <= clause
with t1(PARAMETER_VALUE) as
(
select 'E,C;S,C;I,X;G,T;S,J;S,F;C,S;' from dual
), t2 as
(
select level as rn,
regexp_substr(PARAMETER_VALUE,'([^,]+)',1,level) as str1,
regexp_substr(PARAMETER_VALUE,'([^;]+)',1,level) as str2
from t1
connect by level <= regexp_count(PARAMETER_VALUE,';')
)
select listagg( regexp_substr(str1,'([^;]+$)') ,' ') within group (order by rn) as col1,
listagg( regexp_substr(str2,'([^,]+$)') ,' ') within group (order by rn) as col2
from t2;
COL1 COL2
------------- -------------
E S I G S S C C C X T J F S
Demo
Assuming that you need to separate the input into rows, at the ; delimiters, and then into columns at the , delimiter, you could do something like this:
-- WITH clause included to simulate input data. Not part of the solution;
-- use actual table and column names in the SELECT statement below.
with
t1(id, parameter_value) as (
select 1, 'E,C;S,C;I,X;G,T;S,J;S,F;C,S;' from dual union all
select 2, ',U;,;V,V;' from dual union all
select 3, null from dual
)
-- End of simulated input data
select id,
level as ord,
regexp_substr(parameter_value, '(;|^)([^,]*),', 1, level, null, 2) as col1,
regexp_substr(parameter_value, ',([^;]*);' , 1, level, null, 1) as col2
from t1
connect by level <= regexp_count(parameter_value, ';')
and id = prior id
and prior sys_guid() is not null
order by id, ord
;
ID ORD COL1 COL2
--- --- ---- ----
1 1 E C
1 2 S C
1 3 I X
1 4 G T
1 5 S J
1 6 S F
1 7 C S
2 1 U
2 2
2 3 V V
3 1
Note - this is not the most efficient way to split the inputs (nothing will be very efficient - the data model, which is in violation of First Normal Form, is the reason). This can be improved using standard instr and substr, but the query will be more complicated, and for that reason, harder to maintain.
I generated more input data, to illustrate a few things. You may have several inputs that must be broken up at the same time; that must be done with care. (Note the additional conditions in CONNECT BY). I also illustrate the handling of NULL - if a comma comes right after a semicolon, that means that the "column 1" part of that pair must be NULL. That is shown in the output.
I have a column "col1" value like : 'a,b,x,y,z' (ordered string)
Another column "col2" is like : 'a,x' or 'b,y,z' (ordered string)
All the string values in "col2" are generated by a subquery. So it is not constant.
But, the value in "col1" is constant. That is col1='a,b,x,y,z'
create table test (col1 varchar2(20), col2 varchar2(10));
insert into test values ('a,b,x,y,z','a,x');
insert into test values ('a,b,x,y,z','b,y,z');
Need help with the replacing in one sql.
Need help to replace the elements on "col1" with "col2".
For example,
when col2='a,x', the result should be : 'b,y,z'
when col2='b,y,z', the result should be : 'a,x'
Here is a fun way to do this:
select col1, col2,
ltrim(regexp_replace(translate(replace(col1,','),','||replace(col2,','),',')
,'(.)',',\1'),',') as col3
from test;
That is: (reading the function calls as they are executed, from inside out)
Remove the commas from both strings
Use TRANSLATE() to remove the characters of the second string from the first string
Use REGEXP_REPLACE to add commas before each character of the remaining string
Trim the leading comma
Here's one option; I included the ID column to make it simpler. I hope that a column similar to it exists in your real case.
The idea is:
split each column (col1, col2) to rows
CTE one represents col1's rows
CTE two represents col2's rows
using the MINUS set operator, subtract those two sets of rows
using LISTAGG, aggregate the result
SQL> select * From test;
ID COL1 COL2
---------- -------------------- ----------
1 a,b,x,y,z a,x
2 a,b,x,y,z b,y,z
SQL> with
2 one as
3 (select id, regexp_substr(col1, '[^,]+', 1, column_value) col
4 from test,
5 table(cast(multiset(select level from dual
6 connect by level <= regexp_count(col1, ',') + 1
7 ) as sys.odcinumberlist))
8 ),
9 two as
10 (select id, regexp_substr(col2, '[^,]+', 1, column_value) col
11 from test,
12 table(cast(multiset(select level from dual
13 connect by level <= regexp_count(col2, ',') + 1
14 ) as sys.odcinumberlist))
15 ),
16 t_minus as
17 (select id, col from one
18 minus
19 select id, col from two
20 )
21 select id, listagg(col, ',') within group (order by col) result
22 From t_minus
23 group by id;
ID RESULT
---------- --------------------
1 b,y,z
2 a,x
SQL>
I have a table and I want to group rows that have at most x difference at col2.
For example,
col1 col2
abg 3
abw 4
abc 5
abd 6
abe 20
abf 21
After query I want to get groups such that
group 1: abg 3
abw 4
abc 5
abd 6
group 2: abe 20
abf 21
In this example difference is 1.
How can write such a query?
For Oracle (or anything that supports window functions) this will work:
select col1, col2, sum(group_gen) over (order by col2) as grp
from (
select col1, col2,
case when col2 - lag(col2) over (order by col2) > 1 then 1 else 0 end as group_gen
from some_table
)
Check it on SQLFiddle.
This should get what you need, and changing the gap to that of 5, or any other number is a single change at the #lastVal +1 (vs whatever other difference). The prequery "PreSorted" is required to make sure the data is being processed sequentially so you don't get out-of-order entries.
As each current row is processed, it's column 2 value is stored in the #lastVal for test comparison of the next row, but remains as a valid column "Col2". There is no "group by" as you are just wanting a column to identify where each group is associated vs any aggregation.
select
#grp := if( PreSorted.col2 > #lastVal +1, #grp +1, #grp ) as GapGroup,
PreSorted.col1,
#lastVal := PreSorted.col2 as Col2
from
( select
YT.col1,
YT.col2
from
YourTable YT
order by
YT.col2 ) PreSorted,
( select #grp := 1,
#lastVal := -1 ) sqlvars
try this query, you can use 1 and 2 as input and get you groups:
var grp number(5)
exec :grp :=1
select * from YourTABLE
where (:grp = 1 and col2 < 20) or (:grp = 2 and col2 > 6);