Question

I have query that INSERTS both explicit values and SELECTd content. I’m also doing basic incrementing.

INSERT INTO `table` (`myID`, `myVal1`, `myVal2`) SELECT `myID` + 1, 'explValHere', 'otherValThere')
FROM `table` ORDER BY `myID` DESC LIMIT 0,1

I am doing this as the table has multiple id’s and incrementing within a specific column. So I can’t, as you would first say, use auto incrementing and insert_id.

The problem of course is the insert doesn’t return the select, but can it? Is there a way of running this insert query and returning any of the result?

Answer 1

Since your query has a LIMIT 1 you could store the “result” in a session/user-defined variable. Still two queries but reentrant; each connection is its own session.

<?php
$pdo = new PDO('mysql:host=localhost;dbname=test;charset=utf8', 'localonly', 'localonly');
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
setup($pdo);

$query = "
    INSERT INTO tbl1 (myID, myVal1, myVal2)
    SELECT @foo:=myID+1, 'val1', 'val2' FROM tbl2 WHERE x=0 LIMIT 1
";
$pdo->exec($query);
foreach( $pdo->query('SELECT @foo as foo') as $row ) {
    echo $row['foo'];
}


function setup($pdo) {
    $pdo->exec('CREATE TEMPORARY TABLE tbl1 (myID int, myVal1 varchar(16), myVal2 varchar(16))');
    $pdo->exec('CREATE TEMPORARY TABLE tbl2 (myID int, x int)');
    $pdo->exec('INSERT INTO tbl2 (myID, x) VALUES (1,1),(2,1),(3,0),(4,0),(5,1)');
}

the “first” record in tbl2 having x=0 is (myID=3,x=0) and the script prints 4.

Other than that and stored procedures et al there’s (to my knowledge) nothing like SQLServer’s OUTPUT or postgresql’s RETURNING clause for MySQL.