Stored procedure to fetch entire row from database - mysql

Question

I am a beginner to MYSQL and currently practicing stored procedures. I am trying to create a procedure that should fetch a row of an entire field when given an input parameter. Is there any workaround for this? If yes, then it would be an immense help.
Many Thanks

Answer 1

Welcome to the Forum.
A stored procedure can simple consist of a SELECT statement that returns all the columns in the row you want. e.g.
CREATE PROCEDURE `myproc`(IN `p_id` INT(11))
READS SQL DATA
SELECT id, COL2, COL3, ETC
FROM `mytable`
WHERE id = 'p_id';
If you need to traverse a table, looking at every row that meets some criteria, then you need to DECLARE a "cursor", and use that to fetch the rows you want. Here is a template I use to create new procedures that need to traverse a table - it can be adapted to suit your needs. In this template I nly retrieve two columns from the cursor, but you can retrieve any number. You have to declare a local variable for each column in your SELECT so the FETCH statement has somewhere to put the data it retrieves from the cursor:
CREATE PROCEDURE `traverse_table`()
READS SQL DATA
BEGIN
DECLARE var_id INT(11) UNSIGNED;
DECLARE var_data varchar(16383);
DECLARE done INT DEFAULT FALSE;
DECLARE ecode varchar(1000) ;
DECLARE emsg varchar(1000) ;
DECLARE nextrecord CURSOR FOR # here is the CURSOR DECLARATION
SELECT `myid`,`mydata` # It will return these rows, one
FROM `mytable` # at a time
WHERE `mydata` LIKE "ABC%";
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
DECLARE CONTINUE HANDLER FOR SQLEXCEPTION
BEGIN
GET DIAGNOSTICS CONDITION 1 ecode = RETURNED_SQLSTATE, emsg = MESSAGE_TEXT;
SELECT var_id,var_data,ecode,emsg;
END;
OPEN nextrecord;
FETCH nextrecord into var_id,var_data; # here is the first Fetch
WHILE (done = FALSE) DO
# >>>>>> do something with var_id,var_data here <<<<<<
SET done = FALSE;
FETCH NEXT FROM records into var_id,var_data; # here is the second and subsequent Fetch
END WHILE;
CLOSE nextrecord;
END