I have a function that takes primary keys and separates them with commas.
Oracle function:
create or replace function split(
list in CHAR,
delimiter in CHAR default ','
)
return split_tbl as
splitted split_tbl := split_tbl();
i pls_integer := 0;
list_ varchar2(32767) := list;
begin
loop
i := instr(list_, delimiter);
if i > 0 then
splitted.extend(1);
splitted(splitted.last) := substr(list_, 1, i - 1);
list_ := substr(list_, i + length(delimiter));
else
splitted.extend(1);
splitted(splitted.last) := list_;
return splitted;
end if;
end loop;
end;
and I have this query in SQL Server that returns the data of this query in the function table
select maxUserSalary.id as 'UserSalary'
into #usersalary
from dbo.Split(#usersalary,';') as userid
cross apply (
select top 1 * from User_Salaryas usersalary
where usersalary.User_Id= userid.item
order by usersalary.Date desc
) as maxUserSalary
The problem is, I'm not able to use cross apply in Oracle to throw this data into this function that is returning a table.
How can I use cross apply with Oracle to return this data in function?
You're using Oracle 18c so you can use the CROSS APPLY syntax. Oracle added it (as well as LATERAL and OUTER APPLY ) in 12c.
Here is a simplified version of your logic:
select us.name
, us.salary
from table(split('FOX IN SOCKS,THING ONE,THING TWO')) t
cross apply (select us.name, max(us.salary) as salary
from user_salaries us
where us.name = t.column_value ) us
There is a working demo on db<>fiddle .
If this doesn't completely solve your problem please post a complete question with table structures, sample data and expected output derived from that sample.
I think APC answered your direct question well. As a side note, I wanted to suggest NOT writing your own function to do this at all. There are several existing solutions to split delimited string values into virtual tables that don't require you to create your own custom types, and don't have the performance overhead of context switching between the SQL and PL/SQL engines.
-- example data - remove this to test with your User_Salary table
with User_Salary as (select 1 as id, 'A' as user_id, sysdate as "Date" from dual
union select 2, 'B', sysdate from dual)
-- your query:
select maxUserSalary.id as "UserSalary"
from (select trim(COLUMN_VALUE) as item
from xmltable(('"'||replace(:usersalary, ';', '","')||'"'))) userid -- note ';' delimiter
cross apply (
select * from User_Salary usersalary
where usersalary.User_Id = userid.item
order by usersalary."Date" desc
fetch first 1 row only
) maxUserSalary;
If you run this and pass in 'A;B;C' for :usersalary, you'll get 1 and 2 back.
A few notes:
In this example, I'm using ; as the delimiter, since that's what your query used.
I tried to match your table/column names, but your column name Date is invalid - it's an Oracle reserved keyword, so it has to be put in quotes to be a valid column name.
As a column identifier, "UserSalary" should also have double quotes, not single.
You can't use as in table aliases.
I removed into usersalary, since into is only used with queries which return a single row, and your query can return multiple rows.
Related
I have input like below
I want like below
I was trying with
Sales External?HR?Purchase Department
I did LISTAGG because finally i want in separate columns
Query Output would be like below,
meaning it should search for first occurrence of the separator (in this case "?", it can be anything but not common ones like "-" or "/" as the separator needs to be separate than sting value) and then extract the phrase before the first separator and create one column and put the value. Then it should look for second occurrence of the separator and then extract the word and keep creating columns, there can be multiple separators.
I tried with SPLIT_PART but it does not maintain the sequence in real data scenario and data does not come correct as per sequence.
I also tried with REGEXP_INSTR, but unable to use special characters as separators.
Any thought?
Regex Extract should work for you:
SELECT
REGEXP_SUBSTR_ALL("Sales External?HR?Purchase Department", "(.*)\?")
You can use LATERAL FLATTEN to convert your array into rows:
WITH MY_CTE AS (
SELECT
REGEXP_SUBSTR_ALL("Sales External?HR?Purchase Department", "(.*)\?")
)
SELECT
*
FROM
LATERAL FLATTEN(INPUT => MY_CTE, MODE=> 'ARRAY')
Deeper dive into some more cases: https://dwgeek.com/snowflake-convert-array-to-rows-methods-and-examples.html/
Here's a simplified version of the data. It uses a CTE with array_agg to group the rows. It then changes from arrays to columns. To add more columns, you can use max(), min(), or any_value() functions to get them through the aggregation. (Note that use of any_value() will not allow use of cached results from the result set cache since it's flagged as nondeterministic.)
create or replace table T1 (EMPID int, ROLE string, ACCESS string, ACCESS_LVL string, ITERATION string);
insert into T1(EMPID, ROLE, ACCESS, ACCESS_LVL, ITERATION) values
(1234, 'Sales Rep', 'Specific', 'REGION', 'DEV'),
(1234, 'Purchase Rep', 'Specific', 'EVERY', 'PROD'),
(1234, 'HR', NULL, 'Dept', 'PROD'),
(4321, 'HR', 'Foo', 'Foo', 'Foo')
;
with X as
(
select EMPID
,array_agg(nvl(ROLE,'')) within group (order by ROLE) ARR_ROLE
,array_agg(nvl(ACCESS,'')) within group (order by ROLE) ARR_ACCESS
,array_agg(nvl(ACCESS_LVL,'')) within group (order by ROLE) ARR_ACCESS_LVL
,array_agg(nvl(ITERATION,'')) within group (order by ROLE) ARR_ITERATION
from T1
group by EMPID
)
select EMPID
,ARR_ROLE[0]::string as ROLE1
,ARR_ROLE[1]::string as ROLE2
,ARR_ROLE[2]::string as ROLE3
,ARR_ACCESS[0]::string as ACCESS1
,ARR_ACCESS[1]::string as ACCESS2
,ARR_ACCESS[2]::string as ACCESS3
,ARR_ACCESS_LVL[0]::string as ACCESS_LVL1
,ARR_ACCESS_LVL[1]::string as ACCESS_LVL2
,ARR_ACCESS_LVL[2]::string as ACCESS_LVL3
,ARR_ITERATION[0]::string as ITERATION1
,ARR_ITERATION[1]::string as ITERATION2
,ARR_ITERATION[2]::string as ITERATION3
from X
;
There's nothing particular that seems interesting to sort the rows into the array so that ROLE1, ROLE2, ROLE3, etc. are deterministic. I showed simply sorting on the name of the role, but it could be any order by within that group.
Here's a stored proc that will produce a table result with a dynamic set of columns based on the input string and specified delimiter.
If you are looking for a way to generate dynamic column names based on values, I recommend visiting Felipe Hoffa's blog entry here:
https://medium.com/snowflake/dynamic-pivots-in-sql-with-snowflake-c763933987c
create or replace procedure pivot_dyn_results(input string, delimiter string)
returns table ()
language SQL
AS
declare
max_count integer default 0;
lcount integer default 0;
rs resultset;
stmt1 string;
stmt2 string;
begin
-- Get number of delimiter separated values (assumes no leading or trailing delimiter)
select regexp_count(:input, '\\'||:delimiter, 1) into :max_count from dual;
-- Generate the initial row-based result set of parsed values
stmt1 := 'SELECT * from lateral split_to_table(?,?)';
-- Build dynamic query to produce the pivoted column based results
stmt2 := 'select * from (select * from table(result_scan(last_query_id(-1)))) pivot(max(value) for index in (';
-- initialize look counter for resulting columns
lcount := 1;
stmt2 := stmt2 || '\'' || lcount || '\'';
-- append pivot statement for each column to be represented
FOR l in 1 to max_count do
lcount := lcount + 1;
stmt2 := stmt2 || ',\'' || lcount || '\'';
END FOR;
-- close out the pivot statement
stmt2 := stmt2 || '))';
-- execute the
EXECUTE IMMEDIATE :stmt1 using (input, delimiter);
rs := (EXECUTE IMMEDIATE :stmt2);
return table(rs);
end;
Invocation:
call pivot_dyn_results([string],[delimiter]);
call pivot_dyn_results('Sales External?HR?Billing?Purchase Department','?');
Results:
Here's my code of the SQL Server stored procedure:
SELECT NOTES as DeletionNote
FROM STCRCHF_LOG
WHERE STHTR_ = #transferNo
IF ( ##ROWCOUNT = 0)
If there is data found, I just want to return the string of NOTES. Else if it doesn't have data, I just want to return an empty string or null.
Screenshot (executed stored procedure):
If there is data found. At my program on the web server side it gets the data.
If there is no data. In my program on the web server side it causes a NullReferenceException
If only a single record is possible then:
select coalesce((SELECT NOTES FROM STCRCHF_LOG
WHERE STHTR_ = #transferNo), '') as DeletionNote
If multiple records are possible then the following will ensure at least one row is returned:
SELECT NOTES as DeletionNote FROM STCRCHF_LOG WHERE STHTR_ = #transferNo
union all select '' /* or null if preferred */ where not exists (SELECT 1 FROM STCRCHF_LOG WHERE STHTR_ = #transferNo)
Another way which I like is to use a dummy value and OUTER APPLY like so.
-- sample data
DECLARE #table TABLE (someId INT IDENTITY, Col1 VARCHAR(100));
INSERT #table(Col1) VALUES ('record 1'),('record 2');
DECLARE #id INT = 11;
SELECT f.Col1
FROM (VALUES(NULL)) AS dummy(x)
OUTER APPLY
(
SELECT t.Col1
FROM #table AS t
WHERE t.someId = #id
) AS f;
Check If(DataTable.Rows.Count >0) check at your web programming level to avoid NullReferenceException. Based on the condition you can make the decision what to do with the further logic at web program.
It is always wise idea to handle such exception from programming level. Think of scenario where somebody else make changes in SQL query without knowing the effect of web usages of the code.
I am looking for a way to concatenate the strings of a field within a group by query. So for example, I have a table:
ID COMPANY_ID EMPLOYEE
1 1 Anna
2 1 Bill
3 2 Carol
4 2 Dave
and I wanted to group by company_id to get something like:
COMPANY_ID EMPLOYEE
1 Anna, Bill
2 Carol, Dave
There is a built-in function in mySQL to do this group_concat
PostgreSQL 9.0 or later:
Modern Postgres (since 2010) has the string_agg(expression, delimiter) function which will do exactly what the asker was looking for:
SELECT company_id, string_agg(employee, ', ')
FROM mytable
GROUP BY company_id;
Postgres 9 also added the ability to specify an ORDER BY clause in any aggregate expression; otherwise you have to order all your results or deal with an undefined order. So you can now write:
SELECT company_id, string_agg(employee, ', ' ORDER BY employee)
FROM mytable
GROUP BY company_id;
PostgreSQL 8.4.x:
PostgreSQL 8.4 (in 2009) introduced the aggregate function array_agg(expression) which collects the values in an array. Then array_to_string() can be used to give the desired result:
SELECT company_id, array_to_string(array_agg(employee), ', ')
FROM mytable
GROUP BY company_id;
PostgreSQL 8.3.x and older:
When this question was originally posed, there was no built-in aggregate function to concatenate strings. The simplest custom implementation (suggested by Vajda Gabo in this mailing list post, among many others) is to use the built-in textcat function (which lies behind the || operator):
CREATE AGGREGATE textcat_all(
basetype = text,
sfunc = textcat,
stype = text,
initcond = ''
);
Here is the CREATE AGGREGATE documentation.
This simply glues all the strings together, with no separator. In order to get a ", " inserted in between them without having it at the end, you might want to make your own concatenation function and substitute it for the "textcat" above. Here is one I put together and tested on 8.3.12:
CREATE FUNCTION commacat(acc text, instr text) RETURNS text AS $$
BEGIN
IF acc IS NULL OR acc = '' THEN
RETURN instr;
ELSE
RETURN acc || ', ' || instr;
END IF;
END;
$$ LANGUAGE plpgsql;
This version will output a comma even if the value in the row is null or empty, so you get output like this:
a, b, c, , e, , g
If you would prefer to remove extra commas to output this:
a, b, c, e, g
Then add an ELSIF check to the function like this:
CREATE FUNCTION commacat_ignore_nulls(acc text, instr text) RETURNS text AS $$
BEGIN
IF acc IS NULL OR acc = '' THEN
RETURN instr;
ELSIF instr IS NULL OR instr = '' THEN
RETURN acc;
ELSE
RETURN acc || ', ' || instr;
END IF;
END;
$$ LANGUAGE plpgsql;
How about using Postgres built-in array functions? At least on 8.4 this works out of the box:
SELECT company_id, array_to_string(array_agg(employee), ',')
FROM mytable
GROUP BY company_id;
As from PostgreSQL 9.0 you can use the aggregate function called string_agg. Your new SQL should look something like this: SELECT company_id, string_agg(employee, ', ')
FROM mytable
GROUP BY company_id;
I claim no credit for the answer because I found it after some searching:
What I didn't know is that PostgreSQL allows you to define your own aggregate functions with CREATE AGGREGATE
This post on the PostgreSQL list shows how trivial it is to create a function to do what's required:
CREATE AGGREGATE textcat_all(
basetype = text,
sfunc = textcat,
stype = text,
initcond = ''
);
SELECT company_id, textcat_all(employee || ', ')
FROM mytable
GROUP BY company_id;
As already mentioned, creating your own aggregate function is the right thing to do. Here is my concatenation aggregate function (you can find details in French):
CREATE OR REPLACE FUNCTION concat2(text, text) RETURNS text AS '
SELECT CASE WHEN $1 IS NULL OR $1 = \'\' THEN $2
WHEN $2 IS NULL OR $2 = \'\' THEN $1
ELSE $1 || \' / \' || $2
END;
'
LANGUAGE SQL;
CREATE AGGREGATE concatenate (
sfunc = concat2,
basetype = text,
stype = text,
initcond = ''
);
And then use it as:
SELECT company_id, concatenate(employee) AS employees FROM ...
This latest announcement list snippet might be of interest if you'll be upgrading to 8.4:
Until 8.4 comes out with a
super-effient native one, you can add
the array_accum() function in the
PostgreSQL documentation for rolling
up any column into an array, which can
then be used by application code, or
combined with array_to_string() to
format it as a list:
http://www.postgresql.org/docs/current/static/xaggr.html
I'd link to the 8.4 development docs but they don't seem to list this feature yet.
Following up on Kev's answer, using the Postgres docs:
First, create an array of the elements, then use the built-in array_to_string function.
CREATE AGGREGATE array_accum (anyelement)
(
sfunc = array_append,
stype = anyarray,
initcond = '{}'
);
select array_to_string(array_accum(name),'|') from table group by id;
Following yet again on the use of a custom aggregate function of string concatenation: you need to remember that the select statement will place rows in any order, so you will need to do a sub select in the from statement with an order by clause, and then an outer select with a group by clause to aggregate the strings, thus:
SELECT custom_aggregate(MY.special_strings)
FROM (SELECT special_strings, grouping_column
FROM a_table
ORDER BY ordering_column) MY
GROUP BY MY.grouping_column
Use STRING_AGG function for PostgreSQL and Google BigQuery SQL:
SELECT company_id, STRING_AGG(employee, ', ')
FROM employees
GROUP BY company_id;
I found this PostgreSQL documentation helpful: http://www.postgresql.org/docs/8.0/interactive/functions-conditional.html.
In my case, I sought plain SQL to concatenate a field with brackets around it, if the field is not empty.
select itemid,
CASE
itemdescription WHEN '' THEN itemname
ELSE itemname || ' (' || itemdescription || ')'
END
from items;
If you are on Amazon Redshift, where string_agg is not supported, try using listagg.
SELECT company_id, listagg(EMPLOYEE, ', ') as employees
FROM EMPLOYEE_table
GROUP BY company_id;
According to version PostgreSQL 9.0 and above you can use the aggregate function called string_agg. Your new SQL should look something like this:
SELECT company_id, string_agg(employee, ', ')
FROM mytable GROUP BY company_id;
You can also use format function. Which can also implicitly take care of type conversion of text, int, etc by itself.
create or replace function concat_return_row_count(tbl_name text, column_name text, value int)
returns integer as $row_count$
declare
total integer;
begin
EXECUTE format('select count(*) from %s WHERE %s = %s', tbl_name, column_name, value) INTO total;
return total;
end;
$row_count$ language plpgsql;
postgres=# select concat_return_row_count('tbl_name','column_name',2); --2 is the value
I'm using Jetbrains Rider and it was a hassle copying the results from above examples to re-execute because it seemed to wrap it all in JSON. This joins them into a single statement that was easier to run
select string_agg('drop table if exists "' || tablename || '" cascade', ';')
from pg_tables where schemaname != $$pg_catalog$$ and tableName like $$rm_%$$
Is this possible? I am using ORACLE 10g.
For example: I have 50 tables name A01, A02, A03, A04.........A50.
And all these tables have the "SAME COLUMN NAME"
For example: name, age, location
(Note: The Column Names are the same but not the value in the columns).
In the END... I want to view all data from column: name, age, location FROM ALL tables starting with letter A.
(Note 2: All tables starting with letter A are NOT STATIC, they are dynamic meaning different changes could occur. Example: A01 to A10 could be deleted and A99 Could be added).
Sorry for not clarifying.
DECLARE
TYPE CurTyp IS REF CURSOR;
v_cursor CurTyp;
v_record A01%ROWTYPE;
v_stmt_str VARCHAR2(4000);
BEGIN
for rec in (
select table_name
from user_tables
where table_name like 'A%'
) loop
if v_stmt_str is not null then
v_stmt_str := v_stmt_str || ' union all ';
end if;
v_stmt_str := v_stmt_str || 'SELECT * FROM ' || rec.table_name;
end loop;
OPEN v_cursor FOR v_stmt_str;
LOOP
FETCH v_cursor INTO v_record;
EXIT WHEN v_cursor%NOTFOUND;
-- Read values v_record.name, v_record.age, v_record.location
-- Do something with them
END LOOP;
CLOSE v_cursor;
END;
As per my understanding if you want to view all column names of tables starting with A then try below
select column_name,table_name from user_tab_cols where table_name like 'A%';
If your requirement is something else then specify it clearly.
If understand you correctly and the number of tables is constant then you can create a VIEW once
CREATE VIEW vw_all
AS
SELECT name, age, location FROM A01
UNION ALL
SELECT name, age, location FROM A01
UNION ALL
...
SELECT name, age, location FROM A50
UNION ALL
And then use it
SELECT *
FROM vw_all
WHERE age < 35
ORDER BY name
This returns you all tables you need:
select table_name
from user_tables
where table_name like 'A__';
From this, you can build a dynamic sql statement as:
select listagg('select * from '||table_name,' union all ') within group(order by table_name)
from user_tables
where table_name like 'A__'
This returns actually an SQL statement which contains all tables and the unions:
select * from A01 union all select * from A02 union all select * from A03
And finally execute this via native dynamic sql. You can do that in PL/SQL, so you need a function:
create function getA
query varchar2(32000);
begin
select listagg('select * from '||table_name,' union all ') within group(order by table_name)
into query
from user_tables
where table_name like 'A__';
open res for query;
return res;
end;
Note that what you're doing manually is basically called partitioning, and Oracle has a super-great support already available for that out of the box. I.e. you can have something which looks like a super-huge table, but technically it is stored as a set of smaller tables (and smaller indexes), splitted by a partitioning criteria. For example, if you have millions of payment records, you may partition it by year, this way one physical table contains only a reasonable set of data. Still, you can freely select in this, and if you're hitting data from other partitions, Oracle takes care of pulling those in.
I am displaying records on a page, and I need a way for the user to select a subset of those records to be displayed on another page. These records aren't stored anywhere the are a dynamically generated thing.
What is the best way to in sql to say where a uniqueid is in this list of ids not in a table etc. I know I could dynamically construct the sql with a bunch of ors, but that seems like a hack. anyone else have any suggestions?
this is the best source:
http://www.sommarskog.se/arrays-in-sql.html
create a split function, and use it like:
SELECT
*
FROM YourTable y
INNER JOIN dbo.splitFunction(#Parameter) s ON y.ID=s.Value
I prefer the number table approach
For this method to work, you need to do this one time table setup:
SELECT TOP 10000 IDENTITY(int,1,1) AS Number
INTO Numbers
FROM sys.objects s1
CROSS JOIN sys.objects s2
ALTER TABLE Numbers ADD CONSTRAINT PK_Numbers PRIMARY KEY CLUSTERED (Number)
Once the Numbers table is set up, create this function:
CREATE FUNCTION [dbo].[FN_ListToTable]
(
#SplitOn char(1) --REQUIRED, the character to split the #List string on
,#List varchar(8000)--REQUIRED, the list to split apart
)
RETURNS TABLE
AS
RETURN
(
----------------
--SINGLE QUERY-- --this will not return empty rows
----------------
SELECT
ListValue
FROM (SELECT
LTRIM(RTRIM(SUBSTRING(List2, number+1, CHARINDEX(#SplitOn, List2, number+1)-number - 1))) AS ListValue
FROM (
SELECT #SplitOn + #List + #SplitOn AS List2
) AS dt
INNER JOIN Numbers n ON n.Number < LEN(dt.List2)
WHERE SUBSTRING(List2, number, 1) = #SplitOn
) dt2
WHERE ListValue IS NOT NULL AND ListValue!=''
);
GO
You can now easily split a CSV string into a table and join on it:
select * from dbo.FN_ListToTable(',','1,2,3,,,4,5,6777,,,')
OUTPUT:
ListValue
-----------------------
1
2
3
4
5
6777
(6 row(s) affected)
Your can pass in a CSV string into a procedure and process only rows for the given IDs:
SELECT
y.*
FROM YourTable y
INNER JOIN dbo.FN_ListToTable(',',#GivenCSV) s ON y.ID=s.ListValue
You can use the solution Joel Spolsky recently gave for this problem.
SELECT * FROM MyTable
WHERE ',' + 'comma,separated,list,of,words' + ','
LIKE '%,' + MyTable.word + ',%';
That solution is clever but slow. The better solution is to split the comma-separated string, and construct a dynamic SQL query with the IN() predicate, adding a query parameter placeholder for each element in your list of values:
SELECT * FROM MyTable
WHERE word IN ( ?, ?, ?, ?, ?, ?, ?, ? );
The number of placeholders is what you have to determine when you split your comma-separated string. Then pass one value from that list per parameter.
If you have too many values in the list and making a long IN() predicate is unwieldy, then insert the values to a temporary table, and JOIN against your main table:
CREATE TEMPORARY TABLE TempTableForSplitValues (word VARCHAR(20));
...split your comma-separated list and INSERT each value to a separate row...
SELECT * FROM MyTable JOIN TempTableForSplitValues USING (word);
Also see many other similar questions on SO, including:
Dynamic SQL Comma Delimited Value Query
Passing a varchar full of comma delimited values to a SQL Server IN function
Parameterized Queries with Like and In
Parameterizing a SQL IN clause?