Related
I know this has been answered to some degree with PHP and MYSQL, but I was wondering if someone could teach me the simplest approach to splitting a string (comma delimited) into multiple rows in Oracle 10g (preferably) and 11g.
The table is as follows:
Name | Project | Error
108 test Err1, Err2, Err3
109 test2 Err1
I want to create the following:
Name | Project | Error
108 Test Err1
108 Test Err2
108 Test Err3
109 Test2 Err1
I've seen a few potential solutions around stack, however they only accounted for a single column (being the comma delimited string). Any help would be greatly appreciated.
This may be an improved way (also with regexp and connect by):
with temp as
(
select 108 Name, 'test' Project, 'Err1, Err2, Err3' Error from dual
union all
select 109, 'test2', 'Err1' from dual
)
select distinct
t.name, t.project,
trim(regexp_substr(t.error, '[^,]+', 1, levels.column_value)) as error
from
temp t,
table(cast(multiset(select level from dual connect by level <= length (regexp_replace(t.error, '[^,]+')) + 1) as sys.OdciNumberList)) levels
order by name
EDIT:
Here is a simple (as in, "not in depth") explanation of the query.
length (regexp_replace(t.error, '[^,]+')) + 1 uses regexp_replace to erase anything that is not the delimiter (comma in this case) and length +1 to get how many elements (errors) are there.
The select level from dual connect by level <= (...) uses a hierarchical query to create a column with an increasing number of matches found, from 1 to the total number of errors.
Preview:
select level, length (regexp_replace('Err1, Err2, Err3', '[^,]+')) + 1 as max
from dual connect by level <= length (regexp_replace('Err1, Err2, Err3', '[^,]+')) + 1
table(cast(multiset(.....) as sys.OdciNumberList)) does some casting of oracle types.
The cast(multiset(.....)) as sys.OdciNumberList transforms multiple collections (one collection for each row in the original data set) into a single collection of numbers, OdciNumberList.
The table() function transforms a collection into a resultset.
FROM without a join creates a cross join between your dataset and the multiset.
As a result, a row in the data set with 4 matches will repeat 4 times (with an increasing number in the column named "column_value").
Preview:
select * from
temp t,
table(cast(multiset(select level from dual connect by level <= length (regexp_replace(t.error, '[^,]+')) + 1) as sys.OdciNumberList)) levels
trim(regexp_substr(t.error, '[^,]+', 1, levels.column_value)) uses the column_value as the nth_appearance/ocurrence parameter for regexp_substr.
You can add some other columns from your data set (t.name, t.project as an example) for easy visualization.
Some references to Oracle docs:
REGEXP_REPLACE
REGEXP_SUBSTR
Extensibility Constants, Types, and Mappings (OdciNumberList)
CAST (multiset)
Hierarchical Queries
regular expressions is a wonderful thing :)
with temp as (
select 108 Name, 'test' Project, 'Err1, Err2, Err3' Error from dual
union all
select 109, 'test2', 'Err1' from dual
)
SELECT distinct Name, Project, trim(regexp_substr(str, '[^,]+', 1, level)) str
FROM (SELECT Name, Project, Error str FROM temp) t
CONNECT BY instr(str, ',', 1, level - 1) > 0
order by Name
There is a huge difference between the below two:
splitting a single delimited string
splitting delimited strings for multiple rows in a table.
If you do not restrict the rows, then the CONNECT BY clause would produce multiple rows and will not give the desired output.
For single delimited string, look at Split single comma delimited string into rows
For splitting delimited strings in a table, look at Split comma delimited strings in a table
Apart from Regular Expressions, a few other alternatives are using:
XMLTable
MODEL clause
Setup
SQL> CREATE TABLE t (
2 ID NUMBER GENERATED ALWAYS AS IDENTITY,
3 text VARCHAR2(100)
4 );
Table created.
SQL>
SQL> INSERT INTO t (text) VALUES ('word1, word2, word3');
1 row created.
SQL> INSERT INTO t (text) VALUES ('word4, word5, word6');
1 row created.
SQL> INSERT INTO t (text) VALUES ('word7, word8, word9');
1 row created.
SQL> COMMIT;
Commit complete.
SQL>
SQL> SELECT * FROM t;
ID TEXT
---------- ----------------------------------------------
1 word1, word2, word3
2 word4, word5, word6
3 word7, word8, word9
SQL>
Using XMLTABLE:
SQL> SELECT id,
2 trim(COLUMN_VALUE) text
3 FROM t,
4 xmltable(('"'
5 || REPLACE(text, ',', '","')
6 || '"'))
7 /
ID TEXT
---------- ------------------------
1 word1
1 word2
1 word3
2 word4
2 word5
2 word6
3 word7
3 word8
3 word9
9 rows selected.
SQL>
Using MODEL clause:
SQL> WITH
2 model_param AS
3 (
4 SELECT id,
5 text AS orig_str ,
6 ','
7 || text
8 || ',' AS mod_str ,
9 1 AS start_pos ,
10 Length(text) AS end_pos ,
11 (Length(text) - Length(Replace(text, ','))) + 1 AS element_count ,
12 0 AS element_no ,
13 ROWNUM AS rn
14 FROM t )
15 SELECT id,
16 trim(Substr(mod_str, start_pos, end_pos-start_pos)) text
17 FROM (
18 SELECT *
19 FROM model_param MODEL PARTITION BY (id, rn, orig_str, mod_str)
20 DIMENSION BY (element_no)
21 MEASURES (start_pos, end_pos, element_count)
22 RULES ITERATE (2000)
23 UNTIL (ITERATION_NUMBER+1 = element_count[0])
24 ( start_pos[ITERATION_NUMBER+1] = instr(cv(mod_str), ',', 1, cv(element_no)) + 1,
25 end_pos[iteration_number+1] = instr(cv(mod_str), ',', 1, cv(element_no) + 1) )
26 )
27 WHERE element_no != 0
28 ORDER BY mod_str ,
29 element_no
30 /
ID TEXT
---------- --------------------------------------------------
1 word1
1 word2
1 word3
2 word4
2 word5
2 word6
3 word7
3 word8
3 word9
9 rows selected.
SQL>
A couple of more examples of the same:
SELECT trim(regexp_substr('Err1, Err2, Err3', '[^,]+', 1, LEVEL)) str_2_tab
FROM dual
CONNECT BY LEVEL <= regexp_count('Err1, Err2, Err3', ',')+1
/
SELECT trim(regexp_substr('Err1, Err2, Err3', '[^,]+', 1, LEVEL)) str_2_tab
FROM dual
CONNECT BY LEVEL <= length('Err1, Err2, Err3') - length(REPLACE('Err1, Err2, Err3', ',', ''))+1
/
Also, may use DBMS_UTILITY.comma_to_table & table_to_comma:
http://www.oracle-base.com/articles/9i/useful-procedures-and-functions-9i.php#DBMS_UTILITY.comma_to_table
I would like to propose a different approach using a PIPELINED table function. It's somewhat similar to the technique of the XMLTABLE, except that you are providing your own custom function to split the character string:
-- Create a collection type to hold the results
CREATE OR REPLACE TYPE typ_str2tbl_nst AS TABLE OF VARCHAR2(30);
/
-- Split the string according to the specified delimiter
CREATE OR REPLACE FUNCTION str2tbl (
p_string VARCHAR2,
p_delimiter CHAR DEFAULT ','
)
RETURN typ_str2tbl_nst PIPELINED
AS
l_tmp VARCHAR2(32000) := p_string || p_delimiter;
l_pos NUMBER;
BEGIN
LOOP
l_pos := INSTR( l_tmp, p_delimiter );
EXIT WHEN NVL( l_pos, 0 ) = 0;
PIPE ROW ( RTRIM( LTRIM( SUBSTR( l_tmp, 1, l_pos-1) ) ) );
l_tmp := SUBSTR( l_tmp, l_pos+1 );
END LOOP;
END str2tbl;
/
-- The problem solution
SELECT name,
project,
TRIM(COLUMN_VALUE) error
FROM t, TABLE(str2tbl(error));
Results:
NAME PROJECT ERROR
---------- ---------- --------------------
108 test Err1
108 test Err2
108 test Err3
109 test2 Err1
The problem with this type of approach is that often the optimizer won't know the cardinality of the table function and it will have to make a guess. This could be potentialy harmful to your execution plans, so this solution can be extended to provide execution statistics for the optimizer.
You can see this optimizer estimate by running an EXPLAIN PLAN on the query above:
Execution Plan
----------------------------------------------------------
Plan hash value: 2402555806
----------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
----------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 16336 | 366K| 59 (0)| 00:00:01 |
| 1 | NESTED LOOPS | | 16336 | 366K| 59 (0)| 00:00:01 |
| 2 | TABLE ACCESS FULL | T | 2 | 42 | 3 (0)| 00:00:01 |
| 3 | COLLECTION ITERATOR PICKLER FETCH| STR2TBL | 8168 | 16336 | 28 (0)| 00:00:01 |
----------------------------------------------------------------------------------------------
Even though the collection has only 3 values, the optimizer estimated 8168 rows for it (default value). This may seem irrelevant at first, but it may be enough for the optimizer to decide for a sub-optimal plan.
The solution is to use the optimizer extensions to provide statistics for the collection:
-- Create the optimizer interface to the str2tbl function
CREATE OR REPLACE TYPE typ_str2tbl_stats AS OBJECT (
dummy NUMBER,
STATIC FUNCTION ODCIGetInterfaces ( p_interfaces OUT SYS.ODCIObjectList )
RETURN NUMBER,
STATIC FUNCTION ODCIStatsTableFunction ( p_function IN SYS.ODCIFuncInfo,
p_stats OUT SYS.ODCITabFuncStats,
p_args IN SYS.ODCIArgDescList,
p_string IN VARCHAR2,
p_delimiter IN CHAR DEFAULT ',' )
RETURN NUMBER
);
/
-- Optimizer interface implementation
CREATE OR REPLACE TYPE BODY typ_str2tbl_stats
AS
STATIC FUNCTION ODCIGetInterfaces ( p_interfaces OUT SYS.ODCIObjectList )
RETURN NUMBER
AS
BEGIN
p_interfaces := SYS.ODCIObjectList ( SYS.ODCIObject ('SYS', 'ODCISTATS2') );
RETURN ODCIConst.SUCCESS;
END ODCIGetInterfaces;
-- This function is responsible for returning the cardinality estimate
STATIC FUNCTION ODCIStatsTableFunction ( p_function IN SYS.ODCIFuncInfo,
p_stats OUT SYS.ODCITabFuncStats,
p_args IN SYS.ODCIArgDescList,
p_string IN VARCHAR2,
p_delimiter IN CHAR DEFAULT ',' )
RETURN NUMBER
AS
BEGIN
-- I'm using basically half the string lenght as an estimator for its cardinality
p_stats := SYS.ODCITabFuncStats( CEIL( LENGTH( p_string ) / 2 ) );
RETURN ODCIConst.SUCCESS;
END ODCIStatsTableFunction;
END;
/
-- Associate our optimizer extension with the PIPELINED function
ASSOCIATE STATISTICS WITH FUNCTIONS str2tbl USING typ_str2tbl_stats;
Testing the resulting execution plan:
Execution Plan
----------------------------------------------------------
Plan hash value: 2402555806
----------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
----------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 23 | 59 (0)| 00:00:01 |
| 1 | NESTED LOOPS | | 1 | 23 | 59 (0)| 00:00:01 |
| 2 | TABLE ACCESS FULL | T | 2 | 42 | 3 (0)| 00:00:01 |
| 3 | COLLECTION ITERATOR PICKLER FETCH| STR2TBL | 1 | 2 | 28 (0)| 00:00:01 |
----------------------------------------------------------------------------------------------
As you can see the cardinality on the plan above is not the 8196 guessed value anymore. It's still not correct because we are passing a column instead of a string literal to the function.
Some tweaking to the function code would be necessary to give a closer estimate in this particular case, but I think the overall concept is pretty much explained here.
The str2tbl function used in this answer was originally developed by Tom Kyte:
https://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:110612348061
The concept of associating statistics with object types can be further explored by reading this article:
http://www.oracle-developer.net/display.php?id=427
The technique described here works in 10g+.
Starting from Oracle 12c you could use JSON_TABLE and JSON_ARRAY:
CREATE TABLE tab(Name, Project, Error) AS
SELECT 108,'test' ,'Err1, Err2, Err3' FROM dual UNION
SELECT 109,'test2','Err1' FROM dual;
And query:
SELECT *
FROM tab t
OUTER APPLY (SELECT TRIM(p) AS p
FROM JSON_TABLE(REPLACE(JSON_ARRAY(t.Error), ',', '","'),
'$[*]' COLUMNS (p VARCHAR2(4000) PATH '$'))) s;
Output:
┌──────┬─────────┬──────────────────┬──────┐
│ Name │ Project │ Error │ P │
├──────┼─────────┼──────────────────┼──────┤
│ 108 │ test │ Err1, Err2, Err3 │ Err1 │
│ 108 │ test │ Err1, Err2, Err3 │ Err2 │
│ 108 │ test │ Err1, Err2, Err3 │ Err3 │
│ 109 │ test2 │ Err1 │ Err1 │
└──────┴─────────┴──────────────────┴──────┘
db<>fiddle demo
REGEXP_COUNT wasn't added until Oracle 11i. Here's an Oracle 10g solution, adopted from Art's solution.
SELECT trim(regexp_substr('Err1, Err2, Err3', '[^,]+', 1, LEVEL)) str_2_tab
FROM dual
CONNECT BY LEVEL <=
LENGTH('Err1, Err2, Err3')
- LENGTH(REPLACE('Err1, Err2, Err3', ',', ''))
+ 1;
Here is an alternative implementation using XMLTABLE that allows for casting to different data types:
select
xmltab.txt
from xmltable(
'for $text in tokenize("a,b,c", ",") return $text'
columns
txt varchar2(4000) path '.'
) xmltab
;
... or if your delimited strings are stored in one or more rows of a table:
select
xmltab.txt
from (
select 'a;b;c' inpt from dual union all
select 'd;e;f' from dual
) base
inner join xmltable(
'for $text in tokenize($input, ";") return $text'
passing base.inpt as "input"
columns
txt varchar2(4000) path '.'
) xmltab
on 1=1
;
I had the same problem, and xmltable helped me:
SELECT id, trim(COLUMN_VALUE) text
FROM t, xmltable(('"' || REPLACE(text, ',', '","') || '"'))
I'd like to add another method. This one uses recursive querys, something I haven't seen in the other answers. It is supported by Oracle since 11gR2.
with cte0 as (
select phone_number x
from hr.employees
), cte1(xstr,xrest,xremoved) as (
select x, x, null
from cte0
union all
select xstr,
case when instr(xrest,'.') = 0 then null else substr(xrest,instr(xrest,'.')+1) end,
case when instr(xrest,'.') = 0 then xrest else substr(xrest,1,instr(xrest,'.') - 1) end
from cte1
where xrest is not null
)
select xstr, xremoved from cte1
where xremoved is not null
order by xstr
It is quite flexible with the splitting character. Simply change it in the INSTR calls.
Without using connect by or regexp:
with mytable as (
select 108 name, 'test' project, 'Err1,Err2,Err3' error from dual
union all
select 109, 'test2', 'Err1' from dual
)
,x as (
select name
,project
,','||error||',' error
from mytable
)
,iter as (SELECT rownum AS pos
FROM all_objects
)
select x.name,x.project
,SUBSTR(x.error
,INSTR(x.error, ',', 1, iter.pos) + 1
,INSTR(x.error, ',', 1, iter.pos + 1)-INSTR(x.error, ',', 1, iter.pos)-1
) error
from x, iter
where iter.pos < = (LENGTH(x.error) - LENGTH(REPLACE(x.error, ','))) - 1;
In Oracle 11g and later, you can use a recursive sub-query and simple string functions (which may be faster than regular expressions and correlated hierarchical sub-queries):
Oracle Setup:
CREATE TABLE table_name ( name, project, error ) as
select 108, 'test', 'Err1, Err2, Err3' from dual union all
select 109, 'test2', 'Err1' from dual;
Query:
WITH table_name_error_bounds ( name, project, error, start_pos, end_pos ) AS (
SELECT name,
project,
error,
1,
INSTR( error, ', ', 1 )
FROM table_name
UNION ALL
SELECT name,
project,
error,
end_pos + 2,
INSTR( error, ', ', end_pos + 2 )
FROM table_name_error_bounds
WHERE end_pos > 0
)
SELECT name,
project,
CASE end_pos
WHEN 0
THEN SUBSTR( error, start_pos )
ELSE SUBSTR( error, start_pos, end_pos - start_pos )
END AS error
FROM table_name_error_bounds
Output:
NAME | PROJECT | ERROR
---: | :------ | :----
108 | test | Err1
109 | test2 | Err1
108 | test | Err2
108 | test | Err3
db<>fiddle here
If you have Oracle APEX 5.1 or later installed, you can use the convenient APEX_STRING.split function, e.g.:
select q.Name, q.Project, s.column_value as Error
from mytable q,
APEX_STRING.split(q.Error, ',') s
The second parameter is the delimiter string. It also accepts a 3rd parameter to limit how many splits you want it to perform.
https://docs.oracle.com/en/database/oracle/application-express/20.1/aeapi/SPLIT-Function-Signature-1.html#GUID-3BE7FF37-E54F-4503-91B8-94F374E243E6
i had used the DBMS_UTILITY.comma_to _table function actually its working
the code as follows
declare
l_tablen BINARY_INTEGER;
l_tab DBMS_UTILITY.uncl_array;
cursor cur is select * from qwer;
rec cur%rowtype;
begin
open cur;
loop
fetch cur into rec;
exit when cur%notfound;
DBMS_UTILITY.comma_to_table (
list => rec.val,
tablen => l_tablen,
tab => l_tab);
FOR i IN 1 .. l_tablen LOOP
DBMS_OUTPUT.put_line(i || ' : ' || l_tab(i));
END LOOP;
end loop;
close cur;
end;
i had used my own table and column names
I have a column (status) in a table that contain numbers and values are 1, 2 or 4.
I would like, in a SQL query, add a calculated column (bitStatus) that will store the bitwise oerator OR for the status column of the current line and the column in the previous line.
like so :
| id | status| bitStatus|
|----|-------|----------|
| 1 | 1 | 1 |
| 2 | 2 | 3 |
| 3 | 4 | 7 |
| 4 | 1 | 7 |
So what I did is to use LAG function in oracle but I coudn't figure out how to do it as long as I want to create only on calculated column bitStatus
my query is like :
select id, status,
BITOR(LAG(bitStatus) OVER (ORDER BY 1), status)) AS bitStatus
But as you know, I can't use LAG(bitStatus) when calculating bitStatus.
So how could I make it the desired table.
Thanks in advance.
Would this help?
lines #1 - 6 represent sample data
the TEMP CTE is here to fetch LAG status value (to improve readability)
the final select does the BITOR operation as bitor(a, b) = a - bitand(a, b) + b
SQL> with test (id, status) as
2 (select 1, 1 from dual union all
3 select 2, 2 from dual union all
4 select 3, 1 from dual union all
5 select 4, 4 from dual
6 ),
7 temp as
8 (select id, status,
9 lag(status) over (order by id) lag_status
10 from test
11 )
12 select id,
13 status,
14 status - bitand(status, nvl(lag_status, status)) + nvl(lag_status, status) as bitstatus
15 from temp
16 order by id;
ID STATUS BITSTATUS
---------- ---------- ----------
1 1 1
2 2 3
3 1 3
4 4 5
SQL>
Is it possible to count and also group by comma delimited values in the oracle database table? This is a table data example:
id | user | title |
1 | foo | a,b,c |
2 | bar | a,d |
3 | tee | b |
The expected result would be:
title | count
a | 2
b | 2
c | 1
d | 1
I wanted to use concat like this:
SELECT a.title FROM Account a WHERE concat(',', a.title, ',') LIKE 'a' OR concat(',', a.title, ',') LIKE 'b' ... GROUP BY a.title?
But I'm getting invalid number of arguments on concat. The title values are predefined, therefore I don't mind if I have to list all of them in the query. Any help is greatly appreciated.
This uses simple string functions and a recursive sub-query factoring and may be faster than using regular expressions and correlated joins:
Oracle Setup:
CREATE TABLE account ( id, "user", title ) AS
SELECT 1, 'foo', 'a,b,c' FROM DUAL UNION ALL
SELECT 2, 'bar', 'a,d' FROM DUAL UNION ALL
SELECT 3, 'tee', 'b' FROM DUAL;
Query:
WITH positions ( title, start_pos, end_pos ) AS (
SELECT title,
1,
INSTR( title, ',', 1 )
FROM account
UNION ALL
SELECT title,
end_pos + 1,
INSTR( title, ',', end_pos + 1 )
FROM positions
WHERE end_pos > 0
),
items ( item ) AS (
SELECT CASE end_pos
WHEN 0
THEN SUBSTR( title, start_pos )
ELSE SUBSTR( title, start_pos, end_pos - start_pos )
END
FROM positions
)
SELECT item,
COUNT(*)
FROM items
GROUP BY item
ORDER BY item;
Output:
ITEM | COUNT(*)
:--- | -------:
a | 2
b | 2
c | 1
d | 1
db<>fiddle here
Split titles to rows and count them.
SQL> with test (id, title) as
2 (select 1, 'a,b,c' from dual union all
3 select 2, 'a,d' from dual union all
4 select 3, 'b' from dual
5 ),
6 temp as
7 (select regexp_substr(title, '[^,]', 1, column_value) val
8 from test cross join table(cast(multiset(select level from dual
9 connect by level <= regexp_count(title, ',') + 1
10 ) as sys.odcinumberlist))
11 )
12 select val as title,
13 count(*)
14 From temp
15 group by val
16 order by val;
TITLE COUNT(*)
-------------------- ----------
a 2
b 2
c 1
d 1
SQL>
If titles aren't that simple, then modify REGEXP_SUBSTR (add + sign) in line #7, e.g.
SQL> with test (id, title) as
2 (select 1, 'Robin Hood,Avatar,Star Wars Episode III' from dual union all
3 select 2, 'Mickey Mouse,Avatar' from dual union all
4 select 3, 'The Godfather' from dual
5 ),
6 temp as
7 (select regexp_substr(title, '[^,]+', 1, column_value) val
8 from test cross join table(cast(multiset(select level from dual
9 connect by level <= regexp_count(title, ',') + 1
10 ) as sys.odcinumberlist))
11 )
12 select val as title,
13 count(*)
14 From temp
15 group by val
16 order by val;
TITLE COUNT(*)
------------------------------ ----------
Avatar 2
Mickey Mouse 1
Robin Hood 1
Star Wars Episode III 1
The Godfather 1
SQL>
I know this has been answered to some degree with PHP and MYSQL, but I was wondering if someone could teach me the simplest approach to splitting a string (comma delimited) into multiple rows in Oracle 10g (preferably) and 11g.
The table is as follows:
Name | Project | Error
108 test Err1, Err2, Err3
109 test2 Err1
I want to create the following:
Name | Project | Error
108 Test Err1
108 Test Err2
108 Test Err3
109 Test2 Err1
I've seen a few potential solutions around stack, however they only accounted for a single column (being the comma delimited string). Any help would be greatly appreciated.
This may be an improved way (also with regexp and connect by):
with temp as
(
select 108 Name, 'test' Project, 'Err1, Err2, Err3' Error from dual
union all
select 109, 'test2', 'Err1' from dual
)
select distinct
t.name, t.project,
trim(regexp_substr(t.error, '[^,]+', 1, levels.column_value)) as error
from
temp t,
table(cast(multiset(select level from dual connect by level <= length (regexp_replace(t.error, '[^,]+')) + 1) as sys.OdciNumberList)) levels
order by name
EDIT:
Here is a simple (as in, "not in depth") explanation of the query.
length (regexp_replace(t.error, '[^,]+')) + 1 uses regexp_replace to erase anything that is not the delimiter (comma in this case) and length +1 to get how many elements (errors) are there.
The select level from dual connect by level <= (...) uses a hierarchical query to create a column with an increasing number of matches found, from 1 to the total number of errors.
Preview:
select level, length (regexp_replace('Err1, Err2, Err3', '[^,]+')) + 1 as max
from dual connect by level <= length (regexp_replace('Err1, Err2, Err3', '[^,]+')) + 1
table(cast(multiset(.....) as sys.OdciNumberList)) does some casting of oracle types.
The cast(multiset(.....)) as sys.OdciNumberList transforms multiple collections (one collection for each row in the original data set) into a single collection of numbers, OdciNumberList.
The table() function transforms a collection into a resultset.
FROM without a join creates a cross join between your dataset and the multiset.
As a result, a row in the data set with 4 matches will repeat 4 times (with an increasing number in the column named "column_value").
Preview:
select * from
temp t,
table(cast(multiset(select level from dual connect by level <= length (regexp_replace(t.error, '[^,]+')) + 1) as sys.OdciNumberList)) levels
trim(regexp_substr(t.error, '[^,]+', 1, levels.column_value)) uses the column_value as the nth_appearance/ocurrence parameter for regexp_substr.
You can add some other columns from your data set (t.name, t.project as an example) for easy visualization.
Some references to Oracle docs:
REGEXP_REPLACE
REGEXP_SUBSTR
Extensibility Constants, Types, and Mappings (OdciNumberList)
CAST (multiset)
Hierarchical Queries
regular expressions is a wonderful thing :)
with temp as (
select 108 Name, 'test' Project, 'Err1, Err2, Err3' Error from dual
union all
select 109, 'test2', 'Err1' from dual
)
SELECT distinct Name, Project, trim(regexp_substr(str, '[^,]+', 1, level)) str
FROM (SELECT Name, Project, Error str FROM temp) t
CONNECT BY instr(str, ',', 1, level - 1) > 0
order by Name
There is a huge difference between the below two:
splitting a single delimited string
splitting delimited strings for multiple rows in a table.
If you do not restrict the rows, then the CONNECT BY clause would produce multiple rows and will not give the desired output.
For single delimited string, look at Split single comma delimited string into rows
For splitting delimited strings in a table, look at Split comma delimited strings in a table
Apart from Regular Expressions, a few other alternatives are using:
XMLTable
MODEL clause
Setup
SQL> CREATE TABLE t (
2 ID NUMBER GENERATED ALWAYS AS IDENTITY,
3 text VARCHAR2(100)
4 );
Table created.
SQL>
SQL> INSERT INTO t (text) VALUES ('word1, word2, word3');
1 row created.
SQL> INSERT INTO t (text) VALUES ('word4, word5, word6');
1 row created.
SQL> INSERT INTO t (text) VALUES ('word7, word8, word9');
1 row created.
SQL> COMMIT;
Commit complete.
SQL>
SQL> SELECT * FROM t;
ID TEXT
---------- ----------------------------------------------
1 word1, word2, word3
2 word4, word5, word6
3 word7, word8, word9
SQL>
Using XMLTABLE:
SQL> SELECT id,
2 trim(COLUMN_VALUE) text
3 FROM t,
4 xmltable(('"'
5 || REPLACE(text, ',', '","')
6 || '"'))
7 /
ID TEXT
---------- ------------------------
1 word1
1 word2
1 word3
2 word4
2 word5
2 word6
3 word7
3 word8
3 word9
9 rows selected.
SQL>
Using MODEL clause:
SQL> WITH
2 model_param AS
3 (
4 SELECT id,
5 text AS orig_str ,
6 ','
7 || text
8 || ',' AS mod_str ,
9 1 AS start_pos ,
10 Length(text) AS end_pos ,
11 (Length(text) - Length(Replace(text, ','))) + 1 AS element_count ,
12 0 AS element_no ,
13 ROWNUM AS rn
14 FROM t )
15 SELECT id,
16 trim(Substr(mod_str, start_pos, end_pos-start_pos)) text
17 FROM (
18 SELECT *
19 FROM model_param MODEL PARTITION BY (id, rn, orig_str, mod_str)
20 DIMENSION BY (element_no)
21 MEASURES (start_pos, end_pos, element_count)
22 RULES ITERATE (2000)
23 UNTIL (ITERATION_NUMBER+1 = element_count[0])
24 ( start_pos[ITERATION_NUMBER+1] = instr(cv(mod_str), ',', 1, cv(element_no)) + 1,
25 end_pos[iteration_number+1] = instr(cv(mod_str), ',', 1, cv(element_no) + 1) )
26 )
27 WHERE element_no != 0
28 ORDER BY mod_str ,
29 element_no
30 /
ID TEXT
---------- --------------------------------------------------
1 word1
1 word2
1 word3
2 word4
2 word5
2 word6
3 word7
3 word8
3 word9
9 rows selected.
SQL>
A couple of more examples of the same:
SELECT trim(regexp_substr('Err1, Err2, Err3', '[^,]+', 1, LEVEL)) str_2_tab
FROM dual
CONNECT BY LEVEL <= regexp_count('Err1, Err2, Err3', ',')+1
/
SELECT trim(regexp_substr('Err1, Err2, Err3', '[^,]+', 1, LEVEL)) str_2_tab
FROM dual
CONNECT BY LEVEL <= length('Err1, Err2, Err3') - length(REPLACE('Err1, Err2, Err3', ',', ''))+1
/
Also, may use DBMS_UTILITY.comma_to_table & table_to_comma:
http://www.oracle-base.com/articles/9i/useful-procedures-and-functions-9i.php#DBMS_UTILITY.comma_to_table
I would like to propose a different approach using a PIPELINED table function. It's somewhat similar to the technique of the XMLTABLE, except that you are providing your own custom function to split the character string:
-- Create a collection type to hold the results
CREATE OR REPLACE TYPE typ_str2tbl_nst AS TABLE OF VARCHAR2(30);
/
-- Split the string according to the specified delimiter
CREATE OR REPLACE FUNCTION str2tbl (
p_string VARCHAR2,
p_delimiter CHAR DEFAULT ','
)
RETURN typ_str2tbl_nst PIPELINED
AS
l_tmp VARCHAR2(32000) := p_string || p_delimiter;
l_pos NUMBER;
BEGIN
LOOP
l_pos := INSTR( l_tmp, p_delimiter );
EXIT WHEN NVL( l_pos, 0 ) = 0;
PIPE ROW ( RTRIM( LTRIM( SUBSTR( l_tmp, 1, l_pos-1) ) ) );
l_tmp := SUBSTR( l_tmp, l_pos+1 );
END LOOP;
END str2tbl;
/
-- The problem solution
SELECT name,
project,
TRIM(COLUMN_VALUE) error
FROM t, TABLE(str2tbl(error));
Results:
NAME PROJECT ERROR
---------- ---------- --------------------
108 test Err1
108 test Err2
108 test Err3
109 test2 Err1
The problem with this type of approach is that often the optimizer won't know the cardinality of the table function and it will have to make a guess. This could be potentialy harmful to your execution plans, so this solution can be extended to provide execution statistics for the optimizer.
You can see this optimizer estimate by running an EXPLAIN PLAN on the query above:
Execution Plan
----------------------------------------------------------
Plan hash value: 2402555806
----------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
----------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 16336 | 366K| 59 (0)| 00:00:01 |
| 1 | NESTED LOOPS | | 16336 | 366K| 59 (0)| 00:00:01 |
| 2 | TABLE ACCESS FULL | T | 2 | 42 | 3 (0)| 00:00:01 |
| 3 | COLLECTION ITERATOR PICKLER FETCH| STR2TBL | 8168 | 16336 | 28 (0)| 00:00:01 |
----------------------------------------------------------------------------------------------
Even though the collection has only 3 values, the optimizer estimated 8168 rows for it (default value). This may seem irrelevant at first, but it may be enough for the optimizer to decide for a sub-optimal plan.
The solution is to use the optimizer extensions to provide statistics for the collection:
-- Create the optimizer interface to the str2tbl function
CREATE OR REPLACE TYPE typ_str2tbl_stats AS OBJECT (
dummy NUMBER,
STATIC FUNCTION ODCIGetInterfaces ( p_interfaces OUT SYS.ODCIObjectList )
RETURN NUMBER,
STATIC FUNCTION ODCIStatsTableFunction ( p_function IN SYS.ODCIFuncInfo,
p_stats OUT SYS.ODCITabFuncStats,
p_args IN SYS.ODCIArgDescList,
p_string IN VARCHAR2,
p_delimiter IN CHAR DEFAULT ',' )
RETURN NUMBER
);
/
-- Optimizer interface implementation
CREATE OR REPLACE TYPE BODY typ_str2tbl_stats
AS
STATIC FUNCTION ODCIGetInterfaces ( p_interfaces OUT SYS.ODCIObjectList )
RETURN NUMBER
AS
BEGIN
p_interfaces := SYS.ODCIObjectList ( SYS.ODCIObject ('SYS', 'ODCISTATS2') );
RETURN ODCIConst.SUCCESS;
END ODCIGetInterfaces;
-- This function is responsible for returning the cardinality estimate
STATIC FUNCTION ODCIStatsTableFunction ( p_function IN SYS.ODCIFuncInfo,
p_stats OUT SYS.ODCITabFuncStats,
p_args IN SYS.ODCIArgDescList,
p_string IN VARCHAR2,
p_delimiter IN CHAR DEFAULT ',' )
RETURN NUMBER
AS
BEGIN
-- I'm using basically half the string lenght as an estimator for its cardinality
p_stats := SYS.ODCITabFuncStats( CEIL( LENGTH( p_string ) / 2 ) );
RETURN ODCIConst.SUCCESS;
END ODCIStatsTableFunction;
END;
/
-- Associate our optimizer extension with the PIPELINED function
ASSOCIATE STATISTICS WITH FUNCTIONS str2tbl USING typ_str2tbl_stats;
Testing the resulting execution plan:
Execution Plan
----------------------------------------------------------
Plan hash value: 2402555806
----------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
----------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 23 | 59 (0)| 00:00:01 |
| 1 | NESTED LOOPS | | 1 | 23 | 59 (0)| 00:00:01 |
| 2 | TABLE ACCESS FULL | T | 2 | 42 | 3 (0)| 00:00:01 |
| 3 | COLLECTION ITERATOR PICKLER FETCH| STR2TBL | 1 | 2 | 28 (0)| 00:00:01 |
----------------------------------------------------------------------------------------------
As you can see the cardinality on the plan above is not the 8196 guessed value anymore. It's still not correct because we are passing a column instead of a string literal to the function.
Some tweaking to the function code would be necessary to give a closer estimate in this particular case, but I think the overall concept is pretty much explained here.
The str2tbl function used in this answer was originally developed by Tom Kyte:
https://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:110612348061
The concept of associating statistics with object types can be further explored by reading this article:
http://www.oracle-developer.net/display.php?id=427
The technique described here works in 10g+.
Starting from Oracle 12c you could use JSON_TABLE and JSON_ARRAY:
CREATE TABLE tab(Name, Project, Error) AS
SELECT 108,'test' ,'Err1, Err2, Err3' FROM dual UNION
SELECT 109,'test2','Err1' FROM dual;
And query:
SELECT *
FROM tab t
OUTER APPLY (SELECT TRIM(p) AS p
FROM JSON_TABLE(REPLACE(JSON_ARRAY(t.Error), ',', '","'),
'$[*]' COLUMNS (p VARCHAR2(4000) PATH '$'))) s;
Output:
┌──────┬─────────┬──────────────────┬──────┐
│ Name │ Project │ Error │ P │
├──────┼─────────┼──────────────────┼──────┤
│ 108 │ test │ Err1, Err2, Err3 │ Err1 │
│ 108 │ test │ Err1, Err2, Err3 │ Err2 │
│ 108 │ test │ Err1, Err2, Err3 │ Err3 │
│ 109 │ test2 │ Err1 │ Err1 │
└──────┴─────────┴──────────────────┴──────┘
db<>fiddle demo
REGEXP_COUNT wasn't added until Oracle 11i. Here's an Oracle 10g solution, adopted from Art's solution.
SELECT trim(regexp_substr('Err1, Err2, Err3', '[^,]+', 1, LEVEL)) str_2_tab
FROM dual
CONNECT BY LEVEL <=
LENGTH('Err1, Err2, Err3')
- LENGTH(REPLACE('Err1, Err2, Err3', ',', ''))
+ 1;
Here is an alternative implementation using XMLTABLE that allows for casting to different data types:
select
xmltab.txt
from xmltable(
'for $text in tokenize("a,b,c", ",") return $text'
columns
txt varchar2(4000) path '.'
) xmltab
;
... or if your delimited strings are stored in one or more rows of a table:
select
xmltab.txt
from (
select 'a;b;c' inpt from dual union all
select 'd;e;f' from dual
) base
inner join xmltable(
'for $text in tokenize($input, ";") return $text'
passing base.inpt as "input"
columns
txt varchar2(4000) path '.'
) xmltab
on 1=1
;
I had the same problem, and xmltable helped me:
SELECT id, trim(COLUMN_VALUE) text
FROM t, xmltable(('"' || REPLACE(text, ',', '","') || '"'))
I'd like to add another method. This one uses recursive querys, something I haven't seen in the other answers. It is supported by Oracle since 11gR2.
with cte0 as (
select phone_number x
from hr.employees
), cte1(xstr,xrest,xremoved) as (
select x, x, null
from cte0
union all
select xstr,
case when instr(xrest,'.') = 0 then null else substr(xrest,instr(xrest,'.')+1) end,
case when instr(xrest,'.') = 0 then xrest else substr(xrest,1,instr(xrest,'.') - 1) end
from cte1
where xrest is not null
)
select xstr, xremoved from cte1
where xremoved is not null
order by xstr
It is quite flexible with the splitting character. Simply change it in the INSTR calls.
Without using connect by or regexp:
with mytable as (
select 108 name, 'test' project, 'Err1,Err2,Err3' error from dual
union all
select 109, 'test2', 'Err1' from dual
)
,x as (
select name
,project
,','||error||',' error
from mytable
)
,iter as (SELECT rownum AS pos
FROM all_objects
)
select x.name,x.project
,SUBSTR(x.error
,INSTR(x.error, ',', 1, iter.pos) + 1
,INSTR(x.error, ',', 1, iter.pos + 1)-INSTR(x.error, ',', 1, iter.pos)-1
) error
from x, iter
where iter.pos < = (LENGTH(x.error) - LENGTH(REPLACE(x.error, ','))) - 1;
In Oracle 11g and later, you can use a recursive sub-query and simple string functions (which may be faster than regular expressions and correlated hierarchical sub-queries):
Oracle Setup:
CREATE TABLE table_name ( name, project, error ) as
select 108, 'test', 'Err1, Err2, Err3' from dual union all
select 109, 'test2', 'Err1' from dual;
Query:
WITH table_name_error_bounds ( name, project, error, start_pos, end_pos ) AS (
SELECT name,
project,
error,
1,
INSTR( error, ', ', 1 )
FROM table_name
UNION ALL
SELECT name,
project,
error,
end_pos + 2,
INSTR( error, ', ', end_pos + 2 )
FROM table_name_error_bounds
WHERE end_pos > 0
)
SELECT name,
project,
CASE end_pos
WHEN 0
THEN SUBSTR( error, start_pos )
ELSE SUBSTR( error, start_pos, end_pos - start_pos )
END AS error
FROM table_name_error_bounds
Output:
NAME | PROJECT | ERROR
---: | :------ | :----
108 | test | Err1
109 | test2 | Err1
108 | test | Err2
108 | test | Err3
db<>fiddle here
If you have Oracle APEX 5.1 or later installed, you can use the convenient APEX_STRING.split function, e.g.:
select q.Name, q.Project, s.column_value as Error
from mytable q,
APEX_STRING.split(q.Error, ',') s
The second parameter is the delimiter string. It also accepts a 3rd parameter to limit how many splits you want it to perform.
https://docs.oracle.com/en/database/oracle/application-express/20.1/aeapi/SPLIT-Function-Signature-1.html#GUID-3BE7FF37-E54F-4503-91B8-94F374E243E6
i had used the DBMS_UTILITY.comma_to _table function actually its working
the code as follows
declare
l_tablen BINARY_INTEGER;
l_tab DBMS_UTILITY.uncl_array;
cursor cur is select * from qwer;
rec cur%rowtype;
begin
open cur;
loop
fetch cur into rec;
exit when cur%notfound;
DBMS_UTILITY.comma_to_table (
list => rec.val,
tablen => l_tablen,
tab => l_tab);
FOR i IN 1 .. l_tablen LOOP
DBMS_OUTPUT.put_line(i || ' : ' || l_tab(i));
END LOOP;
end loop;
close cur;
end;
i had used my own table and column names
I have the following table
+-----------+-------+-------+
| Date | Type | Value |
+-----------+-------+-------+
| 1/1/2013 | A | 1 |
| 1/2/2013 | A | 3 |
| 1/3/2013 | A | 5 |
| 1/4/2013 | A | 6 |
| 1/6/2013 | A | 8 |
| 1/7/2013 | A | 1 |
| 1/8/2013 | A | 2 |
+-----------+-------+-------+
I want to sum the value for the previous 3 dates for a certain day so i used this query.
ie: sel_date = 1/3/2013.
select type, sum(value)
from table_name
where date <= seldate
and date > seldate - 3
group by type
Now the problem is, I want to output a table with a given date range computing for the previous 3 days for each date.
ie: sel_date range 1/3/2013 - 1/8/2013
+-----------+-------+------------+
| Date | Type | Sum(Value) |
+-----------+-------+------------+
| 1/3/2013 | A | 9 | // 5 + 3 + 1
| 1/4/2013 | A | 14 | // 6 + 5 + 3
| 1/5/2013 | A | 11 | // 0 + 6 + 5
| 1/6/2013 | A | 14 | // 8 + 0 + 6
| 1/7/2013 | A | 9 | // 1 + 8 + 0
| 1/8/2013 | A | 11 | // 2 + 1 + 8
+-----------+-------+------------+
Is there a way to do this in a single query. I tried reading on partitioning but it is leading me no where.
Use range between in windowing clause:
select dt, type, value,
sum(value) over (order by dt range between 2 preceding and current row) as sv
from t
Test data and output:
create table t (dt date, type varchar2(1), value number(5));
insert into t values (date '2013-01-01', 'A', 1);
insert into t values (date '2013-01-02', 'A', 3);
insert into t values (date '2013-01-03', 'A', 5);
insert into t values (date '2013-01-04', 'A', 6);
insert into t values (date '2013-01-05', 'A', 8);
insert into t values (date '2013-01-06', 'A', 1);
insert into t values (date '2013-01-07', 'A', 2);
insert into t values (date '2013-01-12', 'A', 2);
DT TYPE VALUE SV
----------- ---- ------ ----------
2013-01-01 A 1 1
2013-01-02 A 3 4
2013-01-03 A 5 9
2013-01-04 A 6 14
2013-01-05 A 8 19
2013-01-06 A 1 15
2013-01-07 A 2 11
2013-01-12 A 2 2
You can try with something like this:
with test(Date_, Type, Value ) as
(
select to_date('01/01/2013', 'mm/dd/yyyy'), 'A', 1 from dual union all
select to_date('01/02/2013', 'mm/dd/yyyy'), 'A', 3 from dual union all
select to_date('01/03/2013', 'mm/dd/yyyy'), 'A', 5 from dual union all
select to_date('01/04/2013', 'mm/dd/yyyy'), 'A', 6 from dual union all
select to_date('01/05/2013', 'mm/dd/yyyy'), 'A', 8 from dual union all
select to_date('01/06/2013', 'mm/dd/yyyy'), 'A', 1 from dual union all
select to_date('01/07/2013', 'mm/dd/yyyy'), 'A', 2 from dual
)
select *
from (
select date_, type,
value + nvl(lag(value, 1) over (partition by type order by date_), 0)
+ nvl(lag(value, 2) over (partition by type order by date_), 0) as value
from test
)
where date_ between to_date('01/03/2013', 'mm/dd/yyyy') and to_date('01/07/2013', 'mm/dd/yyyy')
This sums, for each row, the values of the two preceding ones, based on date; the external query is simply used to apply the filter, given that applying it in the internal query would lead to a wrong sum.
The LAG is used to read values from the rows that precede the current row by 1 or 2 positions.
You can use this:
select date1 ,type,
(select sum(t1.value) sumvalue from table_name t1 where t1.date1 between (t2.date1 - 2) and t2.date1 )
from table_name t2
where date1 between startDate and endDate
select t.date, sum(t.value) OVER(ORDER BY t.date ROWS BETWEEN 2 PRECEDING AND 0 FOLLOWING) as Pre_3row_sum
from table_name t