Replace multiple substrings with one expression in Oracle SQL - oracle

I would like to delete multiple substrings from one column. I tried the replace function with the following code:
select replace('testetstestetststst', 'test'||'et'||'s', '')
from dual;
My expected result is ttt, but I get tstst.
In R it works with:
gsub("test|et|s", "", "testetstestetststst")
How can I replace many different substrings with nothing ('') in a column in clob format in Oracle SQL?

You need the REGEXP version of REPLACE:
select regexp_replace('testetstestetststst', 'test|et|s', '')
from dual;
In your code, you are concatenating strings, instead of using an OR operator; that is, your code is equivalent to
select replace('testetstestetststst', 'testets', '')
from dual;

Rather than using regular expressions, you can nest multiple REPLACE functions:
SELECT REPLACE(
REPLACE(
REPLACE(
'testetstestetststst',
'test'
),
'et'
),
's'
)
FROM DUAL;

We can directly use decode function.
select decode(job,'clerk','1','manager','2','salesman','3',4) from emp;
This will replace clerk with 1,manager with 2,salesman with 3 and other values with 4.

Related

Using Quotation operator in sql in dynamic query

I am facing an issue,when I have to use quotation operator in function call.
For example:
Select replace( vstring, Cust_ref_Id, Vdata(vcount).cust_ref_id)
From dual;
Now my value of cust_ref_id holds Apostrophe.
Which I tried to handle using
Select replace( vstring, Cust_ref_Id, Vdata(vcount).q'[cust_ref_id]')
From dual;
But it's not working.
I have to tell Oracle that it needs to handle the apostrophe coming in the value you are receiving from Vdata(i).cust_ref_id.
How can I do that?

How to evaluate an expression in one table field into another?

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!!

How to use replace function in Oracle to remove a string?

In my table, I have data like PAT5DSA-(ALRP), LAR6DAOP-(RAH) etc..But I want to remove the strings like -(xxxx) or -(xxx) which can be any alphabets inside braces. Tried using the below:
select replace(:code,'-(Aa-Zz)',null) from employee;
But this didn't work..Can anyone please help?
We can do a regex replacement using REGEXP_REPLACE:
SELECT REGEXP_REPLACE('PAT5DSA-(ALRP)', '-\(.*?\)', '')
FROM dual;
PAT5DSA
The plain replace() doesn't understand patterns. You could use a regular expression replace, e.g.:
-- CTE for sample data
with cte (code) as (
select 'PAT5DSA-(ALRP)' from dual
union all
select 'LAR6DAOP-(RAH)' from dual
)
select code, regexp_replace(code, '-\(.*?\)$') as result
from cte;
CODE RESULT
-------------- --------------
PAT5DSA-(ALRP) PAT5DSA
LAR6DAOP-(RAH) LAR6DAOP
This will remove anything inside a pair of parentheses which is preceded by a dash, at the end of the original string. If the parentheses to be removed could be anywhere in the string then remove the $.
Use INSTR and SUBSTR:
WITH cteVals AS (SELECT 'PAT5DSA-(ALRP)' AS COL_VAL FROM DUAL UNION ALL
SELECT 'LAR6DAOP-(RAH)' AS COL_VAL FROM DUAL)
SELECT SUBSTR(COL_VAL, 1, INSTR(COL_VAL, '-')-1)
FROM cteVals;
Best of luck.

How to replace single quote with space in column in oracle database

I have a problem in updating a column in oracle which has a single quote.
The following example will clear the problem.
Lets Client name is Lucy'Mark
Now, I want to replace the Single quote with space
After output, it will be Lucy Mark
Now when I tried the following query it is not working as the query will be
select replace (Lucy'Mark , '''', '') from gen_clientvendor_m;
Please let me know the query.
I am using SQL developer
Use the column with client name and add space to the replace statement:
select replace (client_name , '''', ' ') from gen_clientvendor_m;
Multiple single quotes cause headache :) so - have a look at this option:
SQL> with test (name) as
2 (select q'[Lucy'Mark]' from dual)
3 select name,
4 replace(name, chr(39), ' ') result
5 from test;
NAME RESULT
--------- ---------
Lucy'Mark Lucy Mark
SQL>

Oracle appending string to a select statement

I have a column in a oracle table Lic_num char(7 byte)
SELECT column1, 'ABC' + Lic_num
FROM TABLE One
I wanted ABC appended to all the rows that are returned with lic_num
appended to it.
I tried tha above query and it is not working.
In Oracle it's:
SELECT column1, 'ABC' || Lic_num
FROM TABLE_ONE
This would be the way of doing it.
SELECT column1, 'ABC' || Lic_num FROM TABLE_ONE;
SELECT CONCAT(CONCAT(column1, 'ABC'), Lic_num) FROM TABLE_ONE;
If you need you can rename the concatenated Column name using AS keyword so it would be meaningful in terms of reporting.
Below info is included to help someone looking at concatenation in detail.
There are two ways to concatenate Strings in Oracle SQL. Either using CONCAT function or || operator.
CONCAT function allows you to concatenate two strings together
SELECT CONCAT( string1, string2 ) FROM dual;
Since CONCAT function will only allow you to concatenate two values together. If you want to concatenate more values than two, you can nest multiple CONCAT function calls.
SELECT CONCAT(CONCAT('A', 'B'),'C') FROM dual;
An alternative to using the CONCAT function would be to use the || operator
SELECT 'My Name' || 'My Age' FROM dual;

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