I have a column in my oracle database which due reasons beyond my control contains a CSV string e.g.
Item a,Item b,Item c,Item d
I want to run an UPDATE statement to get rid of item c. Thus ending up with
Item a,Item b,Item d
How can I achieve this
You could use the Oracle REPLACE function:
UPDATE table
SET col = replace(col, 'item c', '')
You just need to be careful handling it as part of a CSV, e.g stripping a following comma. This could mean replacing 'item c,' first and then replacing 'item c' to capture both cases.
EDIT: ah, I might have misunderstood. My solution is based on removing a particular string from your CSV - if you are looking to always replace the 3rd item then Vincent's answer is the one you'll need
If you have a fairly recent version of Oracle (I believe regular expressions were introduced in Oracle 10), you can use REGEXP_REPLACE:
UPDATE table SET column = REGEXP_REPLACE(column,'[^\,]+,','',1,3)
(Also, please do violent things to the genius who stored CSV this way in a relational database.)
you could use a combination of INSTR and SUBSTR to remove the third field:
SQL> WITH a AS (SELECT 'Item a,Item b,Item c,Item d' col FROM dual)
2 SELECT substr(col, 1, instr(col, ',', 1, 2))
3 || substr(col, instr(col, ',', 1, 3) + 1) sub
4 FROM a;
SUB
--------------------
Item a,Item b,Item d
Related
I have a table, inside there is a field called x, the x field contain value of '1+2', '1+3' etc, how to get these value and calculate it and save into another field?
For simple arithmetic expressions - and depending on your Oracle version - you could use xmlquery to evaluate. Note that / has special meaning in xml, the operator for division is the keyword div - so you need a replace in case you may have forward slashes in the arithmetic expression. (If you don't have any divisions, you can simplify the query by removing the call to replace.)
Here is an example - including the test data at the top, in a with clause (not part of the solution!)
with
test_data (str) as (
select '1 + 3' from dual union all
select '3 * 5 - 2' from dual union all
select '2/4*6' from dual union all
select '3 * (1 - 3)' from dual
)
select str, xmlquery(replace(str, '/', ' div ') returning content).getNumberVal()
as evaluated_expression
from test_data;
STR EVALUATED_EXPRESSION
----------- --------------------
1 + 3 4
3 * 5 - 2 13
2/4*6 3
3 * (1 - 3) -6
If you only have valid PL/SQL arithmetic expressions in your formulas, then you can use EXECUTE IMMEDIATE to evaluate them.
For this, you'll need to create a function:
create or replace function eval_expression(p_expression in varchar2)
return number is
query varchar2(100);
result number;
begin
query := 'select ' || p_expression || ' from dual';
execute immediate query
into result;
return result;
end eval_expression;
Then you can use this function in UPDATE query:
update t
--val is another field
set t.val = eval_expression(t.x)
Naturally, with EXECUTE IMMEDIATE this query won't be extremely efficient, but it'll work. Also, with dynamic queries we're going into unsafe territory, so make sure that you don't have malicious code among your formulas.
Also, see "Evaluate Expression" on Ask TOM. Tom Kyte used a slightly more civilized approach (dbms_sql package) and created a package with a single variable support.
If the case you have mentioned needs to be considered then I will suggest you use the following query:
select
xmlquery('3+4'
returning content
).getNumberVal()
from
dual;
If More operators are involved except division then the aforementioned query will work but if the division operator is also involved then you must have to replace "/" with " div " keyword. Something like the following:
select
xmlquery(
replace( '20/5', '/', ' div ')
returning content
).getNumberVal()
from
dual;
Now, you can use it in your update statement or anywhere else.
update tab
set tab.result_column_name = xmlquery(t.your_expr_column_name
returning content
).getNumberVal()
update tab
set tab.result_column_name = xmlquery(
replace( t.your_expr_column_name, '/', ' div ')
returning content
).getNumberVal()
Demo
Cheers!!
I need help
i have records 123,456,789 in rows when i am execute like
this one is working
select * from table1 where num1 in('123','456')
but when i am execute
select * from table1 where num1 in(select value from table2)
no resultset found - why?
Check the DataType varchare2 or Number
try
select * from table1 where num1 in(select to_char(value) from table2)
Storing comma separated values could be the cause of problem.
You can try using regexp_substr to split comma.
First and foremost, an important thing to remember: Do not store numbers in character datatypes. Use NUMBER or INTEGER. Secondly, always prefer VARCHAR2 datatype over CHAR if you wish to store characters > 1.
You said in one of your comments that num1 column is of type char(4). The problem with CHAR datatype is that If your string is 3 characters wide, it stores the record by adding extra 1 space character to make it 4 characters. VARCHAR2 only stores as many characters as you pass while inserting/updating and are not blank padded.
To verify that you may run select length(any_char_col) from t;
Coming to your problem, the IN condition is never satisfied because what's actually being compared is
WHERE 'abc ' = 'abc' - Note the extra space in left side operator.
To fix this, one good option is to pad the right side expression with as many spaces as required to do the right comparison.The function RPAD( string1, padded_length [, pad_string] ) could be used for this purpose.So, your query should look something like this.
select * from table1 where num1 IN (select rpad(value,4) from table2);
This will likely utilise an index on the column num1 if it exists.
The other one is to use RTRIM on LHS, which is only useful if there's a function based index on RTRIM(num1)
select * from table1 where RTRIM(num1) in(select value from table2);
So, the takeaway from all these examples is always use NUMBER types to store numbers and prefer VARCHAR2 over CHAR for strings.
See Demo to fully understand what's happening.
EDIT : It seems You are storing comma separated numbers.You could do something like this.
SELECT *
FROM table1 t1
WHERE EXISTS (
SELECT 1
FROM table2 t2
WHERE ',' ||t2.value|| ',' LIKE '%,' || rtrim(t1.num1) || ',%'
);
See Demo2
Storing comma separated values are bound to cause problems, better change it.
Let me tell you first,
You have stored values in table2 which is comma seperated.
So, how could you match your data with table1 and table2.
Its not Possible.
That's why you did not get any values in result set.
I found the Solution using string array
SELECT T.* FROM TABLE1 T,
(SELECT TRIM(VALUE)AS VAL FROM TABLE2)TABLE2
WHERE
TRIM(NUM1) IN (SELECT COLUMN_VALUE FROM TABLE(FUNC_GETSTRING_ARRAY(TABLE2.VAL)))
thanks
I have (and don't own, so I can't change) a table with a layout similar to this.
ID | CATEGORIES
---------------
1 | c1
2 | c2,c3
3 | c3,c2
4 | c3
5 | c4,c8,c5,c100
I need to return the rows that contain a specific category id. I starting by writing the queries with LIKE statements, because the values can be anywhere in the string
SELECT id FROM table WHERE categories LIKE '%c2%';
Would return rows 2 and 3
SELECT id FROM table WHERE categories LIKE '%c3%' and categories LIKE '%c2%'; Would again get me rows 2 and 3, but not row 4
SELECT id FROM table WHERE categories LIKE '%c3%' or categories LIKE '%c2%'; Would again get me rows 2, 3, and 4
I don't like all the LIKE statements. I've found FIND_IN_SET() in the Oracle documentation but it doesn't seem to work in 10g. I get the following error:
ORA-00904: "FIND_IN_SET": invalid identifier
00904. 00000 - "%s: invalid identifier"
when running this query: SELECT id FROM table WHERE FIND_IN_SET('c2', categories); (example from the docs) or this query: SELECT id FROM table WHERE FIND_IN_SET('c2', categories) <> 0; (example from Google)
I would expect it to return rows 2 and 3.
Is there a better way to write these queries instead of using a ton of LIKE statements?
You can, using LIKE. You don't want to match for partial values, so you'll have to include the commas in your search. That also means that you'll have to provide an extra comma to search for values at the beginning or end of your text:
select
*
from
YourTable
where
',' || CommaSeparatedValueColumn || ',' LIKE '%,SearchValue,%'
But this query will be slow, as will all queries using LIKE, especially with a leading wildcard.
And there's always a risk. If there are spaces around the values, or values can contain commas themselves in which case they are surrounded by quotes (like in csv files), this query won't work and you'll have to add even more logic, slowing down your query even more.
A better solution would be to add a child table for these categories. Or rather even a separate table for the catagories, and a table that cross links them to YourTable.
You can write a PIPELINED table function which return a 1 column table. Each row is a value from the comma separated string. Use something like this to pop a string from the list and put it as a row into the table:
PIPE ROW(ltrim(rtrim(substr(l_list, 1, l_idx - 1),' '),' '));
Usage:
SELECT * FROM MyTable
WHERE 'c2' IN TABLE(Util_Pkg.split_string(categories));
See more here: Oracle docs
Yes and No...
"Yes":
Normalize the data (strongly recommended) - i.e. split the categorie column so that you have each categorie in a separate... then you can just query it in a normal faschion...
"No":
As long as you keep this "pseudo-structure" there will be several issues (performance and others) and you will have to do something similar to:
SELECT * FROM MyTable WHERE categories LIKE 'c2,%' OR categories = 'c2' OR categories LIKE '%,c2,%' OR categories LIKE '%,c2'
IF you absolutely must you could define a function which is named FIND_IN_SET like the following:
CREATE OR REPLACE Function FIND_IN_SET
( vSET IN varchar2, vToFind IN VARCHAR2 )
RETURN number
IS
rRESULT number;
BEGIN
rRESULT := -1;
SELECT COUNT(*) INTO rRESULT FROM DUAL WHERE vSET LIKE ( vToFine || ',%' ) OR vSET = vToFind OR vSET LIKE ('%,' || vToFind || ',%') OR vSET LIKE ('%,' || vToFind);
RETURN rRESULT;
END;
You can then use that function like:
SELECT * FROM MyTable WHERE FIND_IN_SET (categories, 'c2' ) > 0;
For the sake of future searchers, don't forget the regular expression way:
with tbl as (
select 1 ID, 'c1' CATEGORIES from dual
union
select 2 ID, 'c2,c3' CATEGORIES from dual
union
select 3 ID, 'c3,c2' CATEGORIES from dual
union
select 4 ID, 'c3' CATEGORIES from dual
union
select 5 ID, 'c4,c8,c5,c100' CATEGORIES from dual
)
select *
from tbl
where regexp_like(CATEGORIES, '(^|\W)c3(\W|$)');
ID CATEGORIES
---------- -------------
2 c2,c3
3 c3,c2
4 c3
This matches on a word boundary, so even if the comma was followed by a space it would still work. If you want to be more strict and match only where a comma separates values, replace the '\W' with a comma. At any rate, read the regular expression as:
match a group of either the beginning of the line or a word boundary, followed by the target search value, followed by a group of either a word boundary or the end of the line.
As long as the comma-delimited list is 512 characters or less, you can also use a regular expression in this instance (Oracle's regular expression functions, e.g., REGEXP_LIKE(), are limited to 512 characters):
SELECT id, categories
FROM mytable
WHERE REGEXP_LIKE('c2', '^(' || REPLACE(categories, ',', '|') || ')$', 'i');
In the above I'm replacing the commas with the regular expression alternation operator |. If your list of delimited values is already |-delimited, so much the better.
For frequent period of time, i'm doing same process of updating few tables with consecutive values. Hope to make this simple an example below,
UPDATE Table_1 SET vchar_val = REPLACE (vchar_val, '.360/', '.370/'),
WHERE vchar_val LIKE 'http://services%.360/%'
AND c_version IN ('ALL', 'N/A', '37.0');
For 37th version, i'm replacing the places where '36' with '37'. The same i'll do for '38' and it continues...This is making me bore and time consuming process as i've 50 plus records like this for different tables for which i'm manually editing all update queries.
So i planned to write a scheduler which i can trigger for each version by giving input as previous version and current version, in which i'll put all this update queries.
Here comes the place where i struck, if i go by giving version values as input, i'm supposed to introduce local parameter to store. HOW CAN I ASSIGN THAT LOCAL VARIABLE TO MY UPDATE SCRIPT.??????
I go with concatenate the texts like
REPLACE (vchar_val, '.'+ #PrevVersion +'/', '.'+ #CurrentVersion +'/')
PrevVer** & CurrentVer** is my local variable with values .360 & .370 resp.
I think i miss quiet piece of code in this snippet as i'm getting error when running this.
Please help me guys to rearrange this code to automate the query or ur comments to do this job in any alternative way...
Thanks
-VIno
begin
for i in 36 .. 50 loop
UPDATE Table_1
SET vchar_val = REPLACE (vchar_val, '.'|| i ||'0/', '.'|| i+1 ||'0/')
WHERE vchar_val LIKE 'http://services%.'|| i ||'0/%'
AND c_version IN ('ALL', 'N/A', i+1 ||'.0');
end loop;
end;
Of course you could do that in one single update with some fancy reg_exp, but I leave that exercice to another fellow stackoverflower :)
Local variable:
declare
my_local_valiable number;
begin
update my_table ... ;
commit;
end;
Autoincrement: sequence
update table_1 set my_field = '.' || my_sequence.nextval where ...;
UPD
Number always in the same position (for example, 2 digits, 10th and 11th symbols in the string):
update table_1 set my_field = substr(my_field, 1, 9) || to_char(to_number(substr(my_field, 10, 2)) + 1) || substr(my_field, 12);
This converts string 'abracadab29ra' to 'abracadab30ra'.
The same with replace:
update table_1 set my_field = replace(my_field, substr(my_field, 10, 2), to_char(to_number(substr(my_field, 10, 2)) + 1));
Number always follows after a string 'value = ' and has two digits:
update table_1 set my_field = replace(my_field, substr(my_field, instr(my_field, 'value = ', 1) + 8, 2), to_char(to_number(substr(my_field, instr(my_field, 'value = ', 1) + 8, 2)) + 1))
This converts string 'my value = 33' to 'my value = 34'.
Select /*+USE_HASH( a b ) */ to_char(date, 'MM/DD/YYYY HH24:MI:SS') as LABEL,
ltrim(rtrim(substr(oled, 9, 16))) as VALUE,
from rrfh a, rrf b,
where ltrim(rtrim(substr(oled, 1, 9))) = 'stata kish'
and a.xyz = b.xyz
The "from " (3rd line) part of the above query is giving me ORA-00936 Missing EXPRESSION error. Please Help me
NOTE :: rrfh table contains no data.
Remove the comma?
select /*+USE_HASH( a b ) */ to_char(date, 'MM/DD/YYYY HH24:MI:SS') as LABEL,
ltrim(rtrim(substr(oled, 9, 16))) as VALUE
from rrfh a, rrf b
where ltrim(rtrim(substr(oled, 1, 9))) = 'stata kish'
and a.xyz = b.xyz
Have a look at FROM
SELECTING from multiple tables You can include multiple tables in the
FROM clause by listing the tables with a comma in between each table
name
Remove the coma at the end of your SELECT statement (VALUE,), and also remove the one at the end of your FROM statement (rrf b,)
This answer is not the answer for the above mentioned question but it is related to same topic and might be useful for people searching for same error.
I faced the same error when I executed below mentioned query.
select OR.* from ORDER_REL_STAT OR
problem with above query was OR is keyword so it was expecting other values when I replaced with some other alias it worked fine.
update INC.PROV_CSP_DEMO_ADDR_TEMP pd
set pd.practice_name = (
select PRSQ_COMMENT FROM INC.CMC_PRSQ_SITE_QA PRSQ
WHERE PRSQ.PRSQ_MCTR_ITEM = 'PRNM'
AND PRSQ.PRAD_ID = pd.provider_id
AND PRSQ.PRAD_TYPE = pd.prov_addr_type
AND ROWNUM = 1
)
This happens every time you insert/ update and you don't use single quotes. When the variable is empty it will result in that error. Fix it by using ''
Assuming the first parameter is an empty variable here is a simple example:
Wrong
nvl( ,0)
Fix
nvl('' ,0)
Put your query into your database software and check it for that error. Generally this is an easy fix