PHP new static 和 new self详解
435
2024-01-10
(PHP 4 >= 4.2.0, PHP 5)
pg_send_query — 发送异步查询
说明
bool pg_send_query ( resource$connection
, string $query
)
bool pg_send_query
( string $query
)
pg_send_query() 向 connection
连接发送异步查询。和 pg_query() 不同，它可以向 PostgreSQL
发送多个查询并用 pg_get_result()
依次得到结果。当执行查询时脚本的执行不会被锁定。用
pg_connection_busy() 来检查连接连接是否为忙（即查询正在执行中）。调用
pg_cancel_query() 则有可能取消查询。
尽管用户可以一次发送多个查询，但用户不能通过正忙的连接发送多个查询。如果向正忙的连接发送了查询，则会等待上一条查询结束并丢弃所有结果。
Example #1 异步查询
<?php
$dbconn = pg_connect("dbname=publisher") or die("Could not connect");
if (!pg_connection_busy($dbconn)) {
pg_send_query($dbconn,"select * from authors; select count(*) from authors;");
}
$res1 = pg_get_result($dbconn);
echo "First call to pg_get_result(): $res1n";
$rows1 = pg_num_rows($res1);
echo "$res1 has $rows1 recordsnn";
$res2 = pg_get_result($dbconn);
echo "second call to pg_get_result(): $res2n";
$rows2 = pg_num_rows($res2);
echo "$res2 has $rows2 recordsn";
?>
上例输出如下：
first call to pg_get_result(): Resource id #3 Resource id #3 has 3 records second call to pg_get_result(): Resource id #4 Resource id #4 has 1 records
参见 pg_query()，pg_cancel_query()，pg_get_result() 和 pg_connection_busy()。
