I tried a lot of ways to use user defined variables in MariaDB version 10.3.22. After failing to use it in my application, I wanted to try with a simple example:
DECLARE #EmpName1 NVARCHAR(50)
SET #EmpName1 = 'Ali'
PRINT #EmpName1
gives Unrecognized statement type. (near "DECLARE" at position 0)
After some digging around I tried using it between delimiters and as a created function:
DELIMITER //
CREATE FUNCTION test
DECLARE #EmpName1 VARCHAR(50)
SET #EmpName1 = 'Ali'
PRINT #EmpName1
END //
DELIMITER;
This gives
Unrecognized data type. (near ")" at position 54)
A "RETURNS" keyword was expected. (near "END" at position 110)
I cannot figure out where the issue might be coming from, as the MariaDB documentation has the same syntax as far as I can see.
Can anyone help solving this issue? My final goal would be to assign the single result of a query to a variable as a string.
A few syntax matters:
Need a () set after the function name, even if no parameters are used:
CREATE FUNCTION test()
A function's return data type must be specified after that: (I used the same type/size as your variable. Can be some other type, of course, depending upon what is being returned)
CREATE FUNCTION test() returns varchar(50)
The use of # with the variables not needed, also missing ; at the end of each line, plus PRINT is invalid:
DECLARE EmpName1 VARCHAR(50);
SET EmpName1 = 'Ali';
-- PRINT EmpName1; see item 4
Functions are expected to return a value:
RETURN EmpName1; -- I simply replaced the PRINT with RETURN here.
Putting that all together, the complete definition becomes:
DELIMITER //
CREATE FUNCTION test() RETURNS VARCHAR(50)
BEGIN
DECLARE EmpName1 VARCHAR(50) DEFAULT '';
SET EmpName1 = 'Ali';
RETURN EmpName1;
END //
DELIMITER ;
Then after that is created, use the function:
SELECT test();
Example interaction:
root#localhost(test) DELIMITER //
-> CREATE FUNCTION test() RETURNS VARCHAR(50)
-> BEGIN
-> DECLARE EmpName1 VARCHAR(50);
-> SET EmpName1 = 'Ali';
-> RETURN EmpName1;
-> END //
Query OK, 0 rows affected (0.07 sec)
root#localhost(test)
root#localhost(test) DELIMITER ;
root#localhost(test) select test();
+--------+
| test() |
+--------+
| Ali |
+--------+
1 row in set (0.09 sec)
Though the website does not use DELIMITER you can also see this in action at this DB fiddle.
Related
I am using mariadb 10.3.9, and have created a user defined aggregate function (UDAF) and placed in a common_schema. This schema contains my utility functions to be used by other schema/databases on the same server.
The issue is that when calling the UDAF while using any other schema, it always return NULL!
The following is to demonstrate the issue:
CREATE SCHEMA IF NOT EXISTS common_schema;
DELIMITER $$
DROP FUNCTION IF EXISTS common_schema.add_ints $$
CREATE FUNCTION common_schema.add_ints(int_1 INT, int_2 INT) RETURNS INT NO SQL
BEGIN
RETURN int_1 + int_2;
END $$
DROP FUNCTION IF EXISTS common_schema.sum_ints $$
CREATE AGGREGATE FUNCTION common_schema.sum_ints(int_val INT) RETURNS INT
BEGIN
DECLARE result INT DEFAULT 0;
DECLARE CONTINUE HANDLER FOR NOT FOUND RETURN result;
LOOP FETCH GROUP NEXT ROW;
SET result = common_schema.add_ints(result, int_val);
END LOOP;
END $$
DELIMITER ;
Now, calling it this way, returns the result as expected:
USE common_schema;
SELECT common_schema.sum_ints(seq)
FROM (SELECT 1 seq UNION ALL SELECT 2) t;
-- result: 3
Calling it using any other schema, it returns NULL:
USE other_schema;
SELECT common_schema.sum_ints(seq)
FROM (SELECT 1 seq UNION ALL SELECT 2) t;
-- result: null
Am I missing something here? Is there any configuration that is missing?
Appreciate your help.
Reported as a Bug https://jira.mariadb.org/browse/MDEV-18100.
As a workaround, create the UDAF in every schema.
I am working on Oracle 11g Db, Having trouble on writing Oracle syntax.
I am trying to pass a number variable to my select query and populate the select query to a cursor.
Declare yr_nr NUMBER;
Begin
yr_nr := 2014;
SELECT DCD.CCY ID, DCD.CCYCDDSC DSC
FROM CCYDCD DCD, CCYEXC EXC
WHERE DCD.CCY = EXC.CCY
AND EXC.YEARNR = yr_nr
End
This select query returns 80 records. How to rewrite this syntax.
Ok, so what you have here is an anonymous block and everything that happens in the block stays in that block. Kinda like Vegas.
In other words there is nothing to handle the result set from your query. When you do this:
declare
[varName] [type]
begin
select foo from bar where column = var ; <--- this has no place to go!
end
When you are at an sqlPlus prompt, sqlPlus has a default record set handler which then processes the returned record set and prints it to the screen.
When you use any third party tool like JDBC or Oracle's own OCI library those provide a record set handler then parse them to you with the appropriate calls to get the data, e.g.:
rs.getInteger([query],[column] ) //which returns the specific value.
That anonymous block is essentially a stored procedure. So you have to have something to do with the result set. This is the cause of the missing "into" error you are getting.
If on the other hand you did something like:
declare
[varName] [type]
result number ;
begin
select count(foo) into result from bar where column = var ;
end
The variable result would have the value of 80 since that is the number of records fetched.
declare
[varName] [type]
cursor thisCursor(p1 in number ) is select foo from bar where column = p1 ;
begin
for rec in thisCursor(varName) loop
If rec.column = [some value] then
doSomething
end if ;
end loop ;
end
Do this would allow you to do something with the result set.
input
Package name (IN)
procedure name (or function name) (IN)
A table indexed by integer, it will contain values that will be used to execute the procedure (IN/OUT).
E.g
let's assume that we want to execute the procedure below
utils.get_emp_num(emp_name IN VARCHAR
emp_last_name IN VARCHAR
emp_num OUT NUMBER
result OUT VARCHAR);
The procedure that we will create will have as inputs:
package_name = utils
procedure_name = get_emp_num
table = T[1] -> name
T[2] -> lastname
T[3] -> 0 (any value)
T[4] -> N (any value)
run_procedure(package_name,
procedure_name,
table)
The main procedure should return the same table that has been set in the input, but with the execution result of the procedure
table = T[1] -> name
T[2] -> lastname
T[3] -> 78734 (new value)
T[4] -> F (new value)
any thought ?
You can achieve it with EXECUTE IMMEDIATE. Basically, you build a SQL statement of the following form:
sql := 'BEGIN utils.get_emp_num(:1, :2, :3, :4); END;';
Then you execute it:
EXECUTE IMMEDIATE sql USING t(1), t(2), OUT t(3), OUT t(4);
Now here comes the tricky part: For each number of parameters and IN/OUT combinations you need a separate EXECUTE IMMEDIATE statement. And to figure out the number of parameters and their direction, you need to query the ALL_ARGUMENTS table first.
You might be able to simplify it by passing the whole table as a bind argument instead of a separate bind argument for each table element. But I haven't quite figured out how you would do that.
And the next thing you should consider: the elements of the table T your using will have a type: VARCHAR, NUMBER etc. So the current mixture where you have both numbers and strings won't work.
BTW: Why do you want such a dynamic call mechanism anyway?
Get from the all_arguments table the argument_name, data_type, in_out, and the position
Build the PLSQL block
DECLARE
loop over argument_name and create the declare section
argument_name data_type if in_out <> OUT then := VALUE OF THE INPUT otherwise NULL
BEGIN
--In the case of function create an additional argument
function_var:= package_name.procedure_name( loop over argument_name);
--use a table of any_data, declare it as global in the package
if function then
package_name.ad_table.EXTEND;
package_name.ad_table(package_name.ad_table.LAST):= function_var;
end if
--loop over argument_name IF IN_OUT <> IN
package_name.ad_table.EXTEND;
package_name.ad_table(package_name.ad_table.LAST):=
if data_type = VARCHAR2 then := ConvertVarchar2(argument_name)
else if NUMBER then ConvertNumber
else if DATE then ConvertDate
...
END;
The result is stored in the table.
To get value use Access* functions
I want to create a function that returns the number of rows in a table called Rating with a where clause.Where am i going wrong before the declare statement and the end statement?
create or replace
FUNCTION get_movies(user IN NUMBER) RETURN NUMBER
IS
DECLARE cnt NUMBER;
BEGIN
SELECT count(*)
INTO cnt
FROM rating
where userid= user;
RETURN cnt;
END;
I will appreciate help.Thanks.
You should not have the DECLARE keyword. You only need that for an anonymous block (or a sub-block).
create or replace
FUNCTION get_movies(p_userid IN NUMBER) RETURN NUMBER
IS
cnt NUMBER;
BEGIN
...
user is a reserved word so I'd suggest not using that as your parameter name. In the where clause I'm not sure if it will use your parameter value, or the name of the user executing the function; which would error as that string value couldn't be implicitly converted to a number.
I want to create a procedure that takes in a string, searches the table and the specified column for that string, and returns a 1 if it finds it and a zero if it does not. I am relatively new to SQL and do not know the syntax or commands very well. I want something like this:
CREATE PROCEDURE dbo.GetUsername
(
#Username NCHAR(10)
)
AS
#boolVariable
SELECT #Username FROM Accounts
RETURN #boolVariable
You don't return a value, but instead supply that in a result set.
CREATE PROCEDURE GetUsername
(
#Username NCHAR(10)
)
AS
SELECT Username FROM Accounts WHERE Username = #UserName;
In your calling code, simply check for the existence of a row in the result set.
I'm not sure if you're looking for mysql or mssql solution.
delimiter //
drop procedure if exists search_string //
create procedure search_string (in str varchar(100))
begin
declare b,r bool;
select count(*) into r from your_table where your_field = str;
if r > 0 then
set b = 1;
else
set b = 0;
end if;
select b;
end; //
delimiter //
call search_string('searched_string');