select my_col from test;
Out:
my_col
x
y
z
How can I change the output of the three rows into an output of a list of three quoted strings in postgresql, so that it looks like:
Out:
'x','y','z'
If I run string_agg(my_val, ''','''), I get
Out:
x','y','z
If I run quote_literal() on top of this output, I get:
Out:
'x'',''y'',''z'
I need this list of quoted strings as an input for the argument of a function (stored procedure). The function works by passing the 'x','y','z' as the argument by hand. Therefore, it is all just about the missing leading and trailing quote.
Side remark, not for the question: it would then get read into the function as variadic _v text[] so that I can check for its values in the function with where t.v = any(_v).
You seem to want:
select string_agg('''' || my_val || '''', ',') my_val_agg
from test
That is: concatenate the quotes around the values before aggregating them - then all that is left is to add the , separator in between.
'''' is there to produce a single quote. We can also use the POSIX syntax in Postgres:
select string_agg(E'\'' || my_val || E'\'', ',') my_val_agg
from test
Related
What I wanted is to place every string inside single qoutes even if it is delimited by a dot something like this:
Input: Hi.Hello.World
Output: 'Hi'.'Hello'.'World'
Note: Inputs can be 2 or more words delimited by a dot
You could try this:
SELECT '''' || REPLACE(string, '.', '''.''') || ''''
FROM yourTable
Demo
The idea here is we replace every dot . with dot in single quotes '.'. This covers all internal dots/quotes. Then, to handle the outside single quotes, we can concatenate them on both sides.
How can I select abcdef.txt from the following string?
abcdef.123.txt
I only know how to select abcdef by doing select substr('abcdef.123.txt',1,6) from dual;
You can using || for concat and substr -3 for right part
select substr('abcdef.123.txt',1,6) || '.' ||substr('abcdef.123.txt',-3) from dual;
or avoiding a concat (like suggested by Luc M)
select substr('abcdef.123.txt',1,7) || substr('abcdef.123.txt',-3) from dual;
A general solution, assuming the input string has exactly two periods . and you want to extract the first and third tokens, separated by one . The length of the "tokens" in the input string can be arbitrary (including zero!) and they can contain any characters other than .
select regexp_replace('abcde.123.xyz', '([^.]*).([^.]*).([^.]*)', '\1.\3') as result
from dual;
RESULT
---------
abcde.xyz
Explanation:
[ ] means match any of the characters between brackets.
^
means do NOT match the characters in the brackets - so...
[^.]
means match any character OTHER THAN .
* means match zero or
more occurrences, as many as possible ("greedy" match)
( ... ) is called a subexpression... see below
'\1.\3 means replace the original string
with the first subexpression, followed by ., followed by the THIRD
subexpression.
Replace the substring of anything surrounded by dots (inclusive) with a single dot. No dependence on lengths of components of the string:
SQL> select regexp_replace('abcdef.123.txt', '\..*\.', '.') fixed
from dual;
FIXED
----------
abcdef.txt
SQL>
I'm having : delimited column like 1:2:3:. I want to get this into 1,2,3. My query looks like,
select name
from status where id IN (SELECT REPLACE(NEXT_LIST,':',',')
FROM status);
but I got an error
ORA-01722: invalid number
(1, 2, 3, 4) is different from ('1, 2, 3, 4'). IN requires the former, a list of values; you give it the latter, a string.
You have two options mainly:
Build the query dynamically, i.e. get the list first, then use this to build a query string.
Tokenize the string. This can be done with a custom pipelined function or a recursive query, maybe also via some XML functions. Google "Oracle tokenize string" to find a method that suits you.
UPDATE Option #3: Use LIKE as in ':1:2:3:4:' like '%:3:%'
(This requires your next_list to contain only simple numbers separated with colons. No leading zeros, no blanks, no other characters.)
select name
from status
where (select ':' || next_list || ':' from status) like '%:' || id || ':%'
i agreed with Thorsten but i wonder if we just replace one more time would it works? i mean like this:
select name
from status where id IN (SELECT replace(REPLACE(NEXT_LIST,':',','),'''','')
FROM status);
The REPLACE function returns a string, so the nested query returns a list of string values (where colons replaced with commas), but not a list of number values. When Oracle engine interprets id IN (str_value) it tries to cast the str_value to number and raises exception ORA-01722: invalid number because there are cases like '1:2:3' which are definetely unparseable.
The "pure sql" approach leads us to using custom function detecting if a number is in a colon-separated list:
-- you need Oracle 12c to use function in the WITH clause
-- on earlier versions just unwrap CASE statement and put it into query
WITH
FUNCTION in_list(p_id NUMBER, p_list VARCHAR2) RETURN NUMBER DETERMINISTIC IS
BEGIN
RETURN CASE WHEN
instr(':' || p_list || ':', ':' || p_id || ':') > 0
THEN 1 ELSE 0 END;
END;
SELECT *
FROM status
WHERE in_list(id, next_list) = 1;
Here I assume that values in the next_list column are strings containing numbers separated with colon without spaces. In common case you shall modify the function to match specific list formats.
I have a number of tables 'App_build', 'Server_build' with a column called 'buildid' and it contains a large number of records. I.e.:
buildid
-----------
Application1_BLD_01
Application1_BLD_02
Application1_BLD_03
Application2_BLD_01
Application3_BLD_01
Application3_BLD_02
Application4_1_0_0_1 - old format to be disregarded
Application4_1_0_0_2
Application4_BLD_03
I want to write a function called getmax(tablename) i.e. getmax('App_build')
which will return a recordset which lists the highest values only. I.e:
buildid
--------
Application1_BLD_03
Application2_BLD_01
Application3_BLD_02
Application4_BLD_03
I am new to SQL so am not sure how to start - I guess I can use a split command and then the MAX function but I have no idea where to start.
Any help will be great.
Assuming current version PostgreSQL 9.2 for lack of information.
Plain SQL
The simple query could look like this:
SELECT max(buildid)
FROM app_build
WHERE buildid !~ '\d+_\d+_\d+_\d+$' -- to exclude old format
GROUP BY substring(buildid, '^[^_]+')
ORDER BY substring(buildid, '^[^_]+');
The WHERE condition used a regular expression:
buildid !~ '\d+_\d+_\d+_\d+$'
Excludes buildid that end in 4 integer numbers divided by _.
\d .. character class shorthand for digits. Only one backslash \ in modern PostgreSQL with standard_conforming_strings = ON.
+ .. 1 or more of preceding atom.
$ .. As last character: anchored to the end of the string.
There may be a cheaper / more accurate way, you did not properly specify the format.
GROUP BY and ORDER BY extract the the string before the first occurrence of _ with substring() as app name to group and order by. The regexp explained:
^ .. As first character: anchor search expression to start of string.
[^_] .. Character class: any chracter that is not _.
Does the same as split_part(buildid, '_', 1). But split_part() may be faster ..
Function
If you want to write a function where the table name is variable, you need dynamic SQL. That is a plpgsql function with EXECUTE:
CREATE OR REPLACE FUNCTION getmax(_tbl regclass)
RETURNS SETOF text AS
$func$
BEGIN
RETURN QUERY
EXECUTE format($$
SELECT max(buildid)
FROM %s
WHERE buildid !~ '\d+_\d+_\d+_\d+$'
GROUP BY substring(buildid, '^[^_]+')
ORDER BY substring(buildid, '^[^_]+')$$, _tbl);
END
$func$ LANGUAGE plpgsql;
Call:
SELECT * FROM getmax('app_build');
Or if you are, in fact, using mixed case identifiers:
SELECT * FROM getmax('"App_build"');
->SQLfiddle demo.
More info on the object identifier class regclass in this related questions:
Table name as a PostgreSQL function parameter
What you want is a groupwise_max. It can be done with MAX() but the usual way is left join:
SELECT b1.buildid
FROM builds AS b1
LEFT JOIN builds AS b2 ON
split_part(b1.buildid, '_', 1)=split_part(b2.buildid, '_', 1)
AND
split_part(b1.buildid, '_', 3)::int<split_part(b2.buildid, '_', 3)::int
WHERE b2.buildid IS NULL;
But since you're using PG it can be done with DISTINCT ON ()
SELECT DISTINCT ON (split_part(buildid, '_', 1)) buildid
FROM builds
ORDER BY split_part(buildid, '_', 1),split_part(buildid, '_', 3)::int DESC
http://sqlfiddle.com/#!12/308bf/9
I am using Postgres and this is the return of a plpgsql function.
point = x||','||y;
The following is the output I get from the function:
"(14.5084692510445),(35.8988013191481)"
The thing is that I would like to output the values surrounded without any brackets. Is it possible to be done?
It depends on the data types involved, which are missing in your question.
For string types use trim():
SELECT trim (x, '()') || ',' || trim (y, '()')
To provide for potential NULL values, you may want to use concat_ws() in addition:
SELECT concat_ws(',', trim (x, '()'), trim (y, '()'))
concat_ws() was introduced with Postgres 9.1.