how can i call stored procedure from the function in mariadb? - mariadb

Question

i want to get count of no.of rows present in table which i pass at runtime to a function.
i have created a procedure and function to execute dynamic queries. function will not allow dynamic query because i am calling procedure from function.
that procedure having dynamic query.
///////procedure///////
CREATE PROCEDURE bizopsgolddev.`test1`(tbnm varchar(100))
begin
declare sql_text varchar(200);
DECLARE EXIT HANDLER FOR SQLEXCEPTION
BEGIN
SELECT CONCAT(sql_text, ' is not valid');
END;
set sql_text=concat('select count(*) from ',tbnm);
SET #SQL := sql_text;
PREPARE stmt FROM #SQL;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
end;
//////function//////
DROP FUNCTION IF EXISTS xyz;
CREATE FUNCTION `xyz`(tname varchar(100)) RETURNS int(11)
begin
declare val int;
call test1(tname);
return 1;
end;
if i execute this //select xyz('axpdc')// it should return rows count
can any one tell me how can i get count by passing table name to function(in mariadb only)

Answer 1

As I understand the question, the solution would be a function that returns the row count of a table with it's name passed to the function as a parameter.
I think this could be done by querying the information_schema database in MariaDB. A function could look like this:
CREATE DEFINER = 'yourUsername'#'192.168.%'
FUNCTION testDataBase.fn_GetRowCount(tableName VARCHAR(128))
RETURNS int(11)
BEGIN
-- This could be a parameter if need it to be.
DECLARE databaseName varchar(40) DEFAULT 'testDataBase';
DECLARE result int DEFAULT -1;
SELECT t.TABLE_ROWS INTO result
FROM information_schema.TABLES t
WHERE t.TABLE_NAME = tableName
AND t.TABLE_SCHEMA = databaseName;
RETURN result;
END
In order for this to work the user mentioned as the definer must have read privilege to the TABLES table in the information_schema database, otherwise you might get an error (tbh, I don't know if this is necessary).
There is a lot of useful information to be grabbed from the information_schema database.