mysqli-multi-query | 易学教程

select every other row in MySQL without depending on any ID?

阅读更多关于 select every other row in MySQL without depending on any ID?

问题 Considering following table that doesn't have any primary key, can I select every other row? col1 col2 2 a 1 b 3 c 12 g first select must find: 2, 3 second select must find: 1, 12 is that possible? 回答1: In unique MySQL fashion: select * from ( select * , @rn := @rn + 1 as rn from Table1 join (select @rn := 0) i ) s where rn mod 2 = 0 -- Use = 1 for the other set Example at SQL Fiddle. 回答2: This works for me. SET @row_number = 0; select* from ( SELECT (@row_number:=@row_number + 1) AS num,

Cannot figure out how to run a mysqli_multi_query and use the results from the last query

阅读更多关于 Cannot figure out how to run a mysqli_multi_query and use the results from the last query

I've never used mysqli_multi_query before and it's boggling my brain, any examples I find on the net aren't helping me to figure out exactly what it is I want to do. Here is my code: <?php $link = mysqli_connect("server", "user", "pass", "db"); if (mysqli_connect_errno()) { printf("Connect failed: %s\n", mysqli_connect_error()); exit(); } $agentsquery = "CREATE TEMPORARY TABLE LeaderBoard ( `agent_name` varchar(20) NOT NULL, `job_number` int(5) NOT NULL, `job_value` decimal(3,1) NOT NULL, `points_value` decimal(8,2) NOT NULL );"; $agentsquery .= "INSERT INTO LeaderBoard (`agent_name`, `job

Speed/best practice flushing mysqli_multi_query()

阅读更多关于 Speed/best practice flushing mysqli_multi_query()

问题 I cringed when Sebastien stated he was disconnecting & reconnecting between each use of mysqli_multi_query() @ Can mysqli_multi_query do UPDATE statements? because it just didn't seem like best practice. However, Craig @ mysqli multi_query followed by query stated in his case that it was faster to disconnect & reconnect between each use of mysqli_multi_query() than to employ mysqli_next_result() . I would like to ask if anyone has further first-hand knowledge or benchmark evidence to suggest

Strict Standards: mysqli_next_result() error with mysqli_multi_query

阅读更多关于 Strict Standards: mysqli_next_result() error with mysqli_multi_query

问题 I have tried using multi_query but I keep getting a strict Standards message popping up. $querystring = \"INSERT INTO responses VALUES(\'1\', \'2\', \'3\', \'4\'); INSERT INTO responses VALUES(\'1\', \'2\', \'3\', \'4\')\"; if (mysqli_multi_query($db, $querystring)) { do { if ($result = mysqli_store_result($db)) { // } } while (mysqli_next_result($db)); } echo \"end\"; The error message I get is: Strict Standards : mysqli_next_result(): There is no next result set. Please, call mysqli_more