My problem is fairly simple. I have table sets that store product sets (more products looking like one on the outside - computer, mouse and keyboard for ex.) it's connected M:N using sets_products table to products table. Each product can have parameters (connected again M:N).
I have a procedure, that generates all parameters as string (for search cache - like 'hdd:120GB, LCD:1440:900, ..'), but now I need to loop through the set's products and call the procedure for each of them. I CAN'T DO IT IN PHP, because this is used in trigger.
I'd like to use something like this (pseudo SQL)
FOREACH(SELECT products_id FROM sets_products WHERE set_id = 1)
generate_parameter_list(product_id,#result)
#param = CONCAT(#param,",",#result);
END FOREACH;
Can this be done in MySQL or not?
Here's the mysql reference for cursors. So I'm guessing it's something like this:
DECLARE done INT DEFAULT 0;
DECLARE products_id INT;
DECLARE result varchar(4000);
DECLARE cur1 CURSOR FOR SELECT products_id FROM sets_products WHERE set_id = 1;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;
OPEN cur1;
REPEAT
FETCH cur1 INTO products_id;
IF NOT done THEN
CALL generate_parameter_list(#product_id, #result);
SET param = param + "," + result; -- not sure on this syntax
END IF;
UNTIL done END REPEAT;
CLOSE cur1;
-- now trim off the trailing , if desired
This can be done with MySQL, although it's highly unintuitive:
CREATE PROCEDURE p25 (OUT return_val INT)
BEGIN
DECLARE a,b INT;
DECLARE cur_1 CURSOR FOR SELECT s1 FROM t;
DECLARE CONTINUE HANDLER FOR NOT FOUND
SET b = 1;
OPEN cur_1;
REPEAT
FETCH cur_1 INTO a;
UNTIL b = 1
END REPEAT;
CLOSE cur_1;
SET return_val = a;
END;//
Check out this guide: mysql-storedprocedures.pdf
Related
Lets suppose I have some SQL script in a scripted calculation view that takes a single value input parameter and generates a string of multiple inputs for an input parameter in another calculation view.
BEGIN
declare paramStr clob;
params = select foo
from bar
where bar.id = :IP_ID;
select '''' || string_agg(foo, ''', ''') || ''''
into paramStr
from :params;
var_out = select *
from "_SYS_BIC"."somepackage/MULTIPLE_IP_VIEW"(PLACEHOLDER."$$IP_IDS$$" => :paramStr);
END
This works as expected. However, if I change the var_out query and try to use the variable in a where clause
BEGIN
...
var_out = select *
from "_SYS_BIC"."somepackage/MULTIPLE_IP_VIEW"
where "IP_IDS" in(:paramStr);
END
the view will activate, but I get no results from the query. No runtime errors, just an empty result set. When I manually pass in the values to the WHERE IN() clause, everything works fine. It seems like an elementary problem to have, but I can't seem to get it to work. I have even tried using char(39) rather than '''' in my concatenation expression, but no banana :(
Ok, so what you are doing here is trying to make the statement dynamic.
For the IN condition, you seem to hope that once you have filled paramStr it would be handled as a set of parameters.
That's not the case at all.
Let's go with your example from the comment: paramStr = ' 'ip1','ip2' '
What happens, when the paramStr gets filled into your code is this:
var_out = select *
from "_SYS_BIC"."somepackage/MULTIPLE_IP_VIEW"
where "IP_IDS" in(' ''ip1'',''ip2'' ');
So, instead of looking for records that match IP_DS = 'ip1' or IP_DS = 'ip2' you are literally looking for records that match IP_DS = ' 'ip1','ip2' '.
One way to work around this is to use the APPLY_FILTER() function.
var_out = select *
from "_SYS_BIC"."somepackage/MULTIPLE_IP_VIEW";
filterStr = ' "IP_IDS" in (''ip1'',''ip2'') ';
var_out_filt = APPLY_FILTER(:var_out, :filterStr) ;
I've written about that some time ago: "On multiple mistakes with IN conditions".
Also, have a look at the documentation for APPLY_FILTER.
The SAP note “2315085 – Query with Multi-Value Parameter on Scripted Calculation View Fails with Incorrect Syntax Error“ actually showcases the APPLY_FILTER() approach that failed when I first tried it.
It also presents an UDF_IN_LIST function to convert a long varchar string with array of items from input parameter to a usable in-list predicate.
Unfortunately, couldn't make it work in sps11 rev 111.03 despite some parameter available (SAP Note 2457876 :to convert error into warning for string length overflow) - (range 3) string is too long exception
then ALTER SYSTEM ALTER CONFIGURATION ('indexserver.ini', 'System') set ('sqlscript', 'typecheck_procedure_input_param') = 'false' WITH RECONFIGURE;
-recompile the Calc View
then
select * from :var_tempout where OBJECT_ID in (select I_LIST from "BWOBJDES"."CROSS_AREA::UDF_INLIST_P"(:in_objectids,','));
invalid number exception - invalid number
But taking the scripting out of the function makes it work...
For this SPS 11 level APPLY_FILTER seems to be the only workaround. And it is really hard to say what would be the rev on SPS 12 to go in order to have it.
FUNCTION "BWOBJDES"."CROSS_AREA::UDF_INLIST_P"(str_input nvarchar(5000),
delimiter nvarchar(10))
RETURNS table ( I_LIST INTEGER ) LANGUAGE SQLSCRIPT SQL SECURITY INVOKER AS
/********* Begin Function Script ************/
BEGIN
DECLARE cnt int;
DECLARE temp_input nvarchar(128);
DECLARE slice NVARCHAR(10) ARRAY;
temp_input := :str_input;
cnt := 1;
WHILE length(temp_input) > 0 DO
if instr(temp_input, delimiter) > 0 then
slice[:cnt] := substr_before(temp_input,delimiter);
temp_input := substr_after(temp_input,delimiter);
cnt := :cnt + 1;
else
slice[:cnt] := temp_input;
break;
end if;
END WHILE;
tab2 = UNNEST(:slice) AS (I_LIST);
return select I_LIST from :tab2;
END;
CREATE PROCEDURE "MY_SCRIPTED_CV/proc"( IN numbers NVARCHAR(5000), OUT
var_out
MY_TABLE_TYPE ) language sqlscript sql security definer reads sql data with
result view
"MY_SCRIPTED_CV" as
/********* Begin Procedure Script ************/
BEGIN
-- not working
--var_out = select * from MY_TABLE where NUMBER in (select I_LIST from
--UDF_INLIST_P(:numbers,','));
-- working
DECLARE cnt int;
DECLARE temp_input nvarchar(128);
DECLARE slice NVARCHAR(13) ARRAY;
DECLARE delimiter VARCHAR := ',';
temp_input := replace(:numbers, char(39), '');
cnt := 1;
WHILE length(temp_input) > 0 DO
if instr(temp_input, delimiter) > 0 then
slice[:cnt] := substr_before(temp_input,delimiter);
temp_input := substr_after(temp_input,delimiter);
cnt := :cnt + 1;
else
slice[:cnt] := temp_input;
break;
end if;
END WHILE;
l_numbers = UNNEST(:slice) AS (NUMBER);
var_out=
SELECT *
FROM MAIN AS MA
INNER JOIN l_numbers as LN
ON MAIN.NUMBER = LN.NUMBER
END;
I know, this is a quite old thread but nevertheless my findings based what I read in here from Jenova might be interesting for others. Thatswhy I am writing them down.
I was faced with the same problem. Users can sent multiple entrie in an input parameter in a calc view I have to optimize. Unluckily I run into the same problem like Jenova and others before. And, no, imho this is not about dynamic view execution or dynamic sql, but about processing in lists in a clean way in a scripted calc view or table function if they are send in an input parameter.
Lars' proposal to use APPLY_FILTER is not applicable in my case, since I cannot use a complex statement in the APPLY_FILTER function itself. I have to materialize the whole amount of data in the select, which result I can assign to APPLY_FILTER and then execute the filtering. I want to see the filtering applied in the first step not after materializing data which is not appearing in the result of the filter application.
So I used a hdbtablefunction to create a function performing the parameter string cleanup and the transformation into an array and afterwards it is returning the result of the UNNEST function.
Since the result of the function is a table it can be used as a table inside the scripted view or tablefunction - in joins, subselects and so on.
This way I am able to process user input lists as expected, fast and with much less resource consumption.
FUNCTION "_SYS_BIC"."package1::transparam" (ip_string NVARCHAR(500) )
RETURNS table ( "PARAMETER" nvarchar(100))
LANGUAGE SQLSCRIPT
SQL SECURITY INVOKER AS
v_test varchar(1000);
IP_DELIMITER VARCHAR(1) := ',';
v_out VARCHAR(100):='';
v_count INTEGER:=1;
v_substr VARCHAR(1000):='';
v_substr2 VARCHAR(1000):='';
id INTEGER array;
val VARCHAR(100) array;
BEGIN
--
v_substr:=:ip_string;
v_substr := REPLACE(:v_substr, '''', '');
v_substr := REPLACE(:v_substr, ' ', '');
while(LOCATE (:v_substr, :ip_delimiter) > 0 ) do
-- find value
v_out := SUBSTR(v_substr, 0, LOCATE (:v_substr, :ip_delimiter) - 1 );
-- out to output
val[v_count]:=v_out;
-- increment counter
v_count:=:v_count+1;
-- new substring for search
v_substr2 := SUBSTR(:v_substr, LOCATE (:v_substr, :ip_delimiter) + 1, LENGTH(:v_substr));
v_substr := v_substr2;
END while;
IF(LOCATE (:v_substr, :ip_delimiter) = 0 AND LENGTH(:v_substr) > 0) THEN
-- no delimiter in string
val[v_count]:=v_substr;
END IF;
-- format output as tables
rst = unnest(:VAL) AS ("PARAMETER");
RETURN SELECT * FROM :rst;
END;
can be called like
select * from "package1.transparam"('''BLU'',''BLA''')
returning table with two lines
PARAMETER
---------
BLU
BLA
The most comprehensive explanation is here:
https://blogs.sap.com/2019/01/17/passing-multi-value-input-parameter-from-calculation-view-to-table-function-in-sap-hana-step-by-step-guide/
Creating custom function splitting string into multiple values
Then inner/left outer join can be used to filter.
I Have below cursor in the code.
CURSOR cur1
IS
SELECT a, b, c, d,
FROM EMP;
BEGIN
--Stored procedure logic
END
This curosr is getting information from EMP table.
But I need to change is as per below
There is a table (Table1) with Key Value pairs.
If the Table1 value is TRUE then the cursor should be created with STUDENT table
If the table1 value is FALSE then the cursor should be created with EMP table.
I can check the Value in the Table1 as below
select t.value into variable1 from Table1 t where s.key='xxxxx';
And I want write something like
IF variable1 := 'true'
curosr created with STUDENT
ELSE
curosr created with EMP
END IF
BEGIN
--Stored procedure logic
END
How to do it?
In another way you can just keep two CURSORS for those two scenarios and OPEN them on the condition. Declaring two CURSORS will not affect to the performance; you should be careful when OPEN a CURSOR and FETCHING from it.
PROCEDURE Get_Details_On_Condition ( name_ OUT VARCHAR2, isEmp IN BOOLEAN )
IS
CURSOR get_emp IS
SELECT name
FROM EMP;
CURSOR get_std IS
SELECT name
FROM STUDENT;
BEGIN
IF isEmp THEN
OPEN get_emp ;
FETCH get_emp INTO name_ ;
CLOSE get_emp ;
ELSE
OPEN get_std ;
FETCH get_std INTO name_ ;
CLOSE get_std ;
END IF;
RETURN name_;
END Get_Details_On_Condition;
Using if .. else construct is not proper (neither supported). You can use REF cursor to achieve the same like below.
DECLARE type cur1 REF CURSOR;
c1 cur1;
BEGIN
IF (variable1 := 'true') THEN
OPEN c1 FOR 'SELECT * FROM STUDENT';
ELSE
OPEN c1 FOR 'SELECT * FORM EMP';
END IF ;
END;
Idea taken from Oracle Community Forum Post
NOTE: I didn't included the entire code block (I mean cursor processing, closing etc) cause the main concern here is "How he will declare/define conditional cursor". So, pointed that particular in my code snippet. Since, rest of the part like processing the cursor and closing can be directly be found in Oracle specification.
For a complete code block, you can refer the answer given by Harsh
I would prefer to solve this without using dynamic SQL. If the code to process the results is the same for both tables, then it is reasonable to assume that the columns are the same (or equivalent) as well. My inclination would be to solve this using UNION and sub-queries:
DECLARE
CURSOR cur1 IS
SELECT a, b, c, d
FROM emp
WHERE NOT EXISTS
(SELECT *
FROM table1
WHERE s.key = 'xxxxx' AND t.VALUE = 'true')
UNION ALL
SELECT a, b, c, d
FROM student
WHERE EXISTS
(SELECT *
FROM table1
WHERE s.key = 'xxxxx' AND t.VALUE = 'true');
BEGIN
--Stored procedure logic
END;
The link provided by Rahul indicates the correct way to solve the problem. From the Oracle community forum post posted by Rahul, I have taken the code snippet through which the code could run successfully.
Rahul: Please do not take this as a redundant answer as I could not comment on your answer to help shyam to take the code snippet in the link posted by you.
Declare
TYPE cv_typ IS REF CURSOR;
cv cv_typ;
Begin
If(condition1 is TRUE) then
open cv FOR
'Select * from table_name1';
EXIT WHEN cv%NOTFOUND;
ELSE
open cv FOR
'Select * from table_name2';
EXIT WHEN cv%NOTFOUND;
End If;
CLOSE cv;
END;
Thanks & Regards,
Harsh
You can move the OPEN outside IF statement:
DECLARE type cur1 REF CURSOR;
c1 cur1;
vSQL VARCHAR2(1000);
BEGIN
IF (variable1 = 'true') THEN
vSQL := 'SELECT * FROM STUDENT';
ELSE
vSQL := 'SELECT * FORM EMP';
END IF;
OPEN c1 FOR vSQL;
--procedure logic
CLOSE c1;
END;
I want to count the rows of a number of tables. But the table name should be used dynamically. I want to do that within one SQL statement.
I tried it with
BEGIN ATOMIC
FOR tmp AS (
SELECT tabschema || '.' || tabname tbl
FROM syscat.tables WHERE tabname LIKE '%CD') DO
(SELECT COUNT(*) FROM tmp.tbl);
END FOR;
END
but I receive the error
DB21034E The command was processed as an SQL statement because it was not a
valid Command Line Processor command. During SQL processing it returned:
SQL0204N "TMP.TBL" is an undefined name. LINE NUMBER=1. SQLSTATE=42704
and found no other working solution...
Is there a solution for that?
Thanks in advance.
I assume that your SELECT COUNT(*) FROM tmp.tbl should translate in multiple statements like
select count(*) from TABLECD
select count(*) from TABLE2CD
...
However, your query will try to do a count of the table TBL in the schema TMP.
You'll have to prepare the complete SQL statement, store it in a variable and pass it to the PREPARE statement (documentation ).
A rather complete stored procedure which somewhat fits your requirements can be found here . The result of the counts will be stored in a table COUNTERS which you can query afterwards.
//edit: this is the example from the topic, adapt to work (not tested since I have no DB2 instance to test atm):
CREATE PROCEDURE tableCount()
LANGUAGE SQL
BEGIN
DECLARE SQLCODE INTEGER DEFAULT 0;
DECLARE SQLSTATE CHAR(5);
DECLARE vTableName VARCHAR(20);
DECLARE vTableCount INTEGER;
DECLARE stmt varchar(2000);
DECLARE not_found CONDITION FOR SQLSTATE '02000';
DECLARE c1 CURSOR FOR
SELECT tabname from syscat.tables where tabschema='DB2ADMIN';
DECLARE C2 CURSOR FOR S2
DECLARE CONTINUE HANDLER FOR not_found
SET stmt = '';
Delete from COUNTERS;
OPEN c1;
getRows:
LOOP
FETCH c1 INTO vTableName;
IF SQLCODE = 0 THEN
SET stmt ='SELECT Count(*) FROM ' || vTableName;
PREPARE S2 FROM stmt;
OPEN C2;
SET vTableCount = 0;
FETCH C2 INTO vTableCount;
INSERT INTO COUNTERS (tableName, tableCount)
VALUES (vTableName, vTableCount);
CLOSE C2;
ELSE
LEAVE getRows;
END IF;
END LOOP getRows;
CLOSE c1;
END
I wanted to know how to insert into a table using stored procedures in DB2 using SQL.
I have created a table as follows:
create table ADCLIBT.Itest
(ITNBR CHAR(15) CCSID 65535 NOT NULL DEFAULT '');
This table contains a list of items. Using this list I want to insert various other fields to another table. But, just for example sake, let's say I just want to insert these values one by one using cursors.
I have written the stored procedure as follows:
create procedure ADCLIBT.itest1()
LANGUAGE SQL
BEGIN
DECLARE itemno char(15);
DECLARE END_TABLE INT DEFAULT 0;
DECLARE not_found CONDITION FOR SQLSTATE '20000';
DECLARE c CURSOR FOR
select ITNBR from ADCLIBT.ITEMAT;
DECLARE CONTINUE HANDLER FOR not_found
SET END_TABLE = 1;
open c;
fetch from c into itemno;
WHILE END_TABLE = 0 DO
insert into ADCLIBT.ITEST
(ITNBR)
values
(select a.ITNBR from ADCLIBT.ITEMAT a where ITNBR=itemno GROUP BY a.ITNBR);
END WHILE;
Close c;
END;
This is giving me an infinite loop. Can anyone please tell me how do I stop the infinite loop and insert these records. I want to use the cursor because I want to further use itemno to compare and get single results.
You are opening the cursor but not feching in the while, you must do a fetch in the while of the cursor. Here an example from the IBM documentation.
CREATE PROCEDURE sum_salaries(OUT sum INTEGER) LANGUAGE SQL
BEGIN
DECLARE SQLSTATE CHAR(5) DEFAULT '00000';
DECLARE p_sum INTEGER;
DECLARE p_sal INTEGER;
DECLARE c CURSOR FOR SELECT SALARY FROM EMPLOYEE;
SET p_sum = 0;
OPEN c;
FETCH FROM c INTO p_sal;
WHILE(SQLSTATE = '00000') DO
SET p_sum = p_sum + p_sal;
FETCH FROM c INTO p_sal;
END WHILE;
CLOSE c;
SET sum = p_sum;
END%
I am writing a trigger in DB2. Inside that i wanted to use a loop.
This is to iterate through a set of values returned from a select statement.
How can this be done?
Anybody please share a tutorial or link which explains this.
Also is it ok to have nested loop?
You can use a cursor in your trigger:
http://en.wikipedia.org/wiki/Cursor_%28databases%29
A simple cursor example looks like this:
DECLARE SQLSTATE CHAR(5) DEFAULT '00000';
DECLARE p_sum INTEGER;
SET p_sum = 0;
DECLARE p_sal INTEGER;
DECLARE c CURSOR FOR SELECT SALARY FROM EMPLOYEE;
OPEN c;
FETCH FROM c INTO p_sal;
WHILE(SQLSTATE = '00000') DO
SET p_sum = p_sum + p_sal;
FETCH FROM c INTO p_sal;
END WHILE;
CLOSE c;