请教个sql语法问题

2016-07-07 15:02 来源：www.chinab4c.com 作者：ecshop专家

$sql = "SELECT a.act_id, a.goods_id, a.goods_name, a.ext_info, g.goods_thumb ".
"FROM " . $GLOBALS['ecs']->table('goods_activity') . " AS a," .
$GLOBALS['ecs']->table('goods') . " AS g" .
" WHERE a.goods_id = g.goods_id" .
" AND a.act_type = '" . GAT_AUCTION . "'" .
" AND a.is_finished = 0" .
" AND a.start_time <= '$now'" .
" AND a.end_time >= '$now'" .
" AND g.is_delete = 0" .
" ORDER BY a.start_time DESC" .
" LIMIT $limit";
里面的"."FROM " . $GLOBALS['ecs']->table('goods_activity') . " AS a," .里面的句号
.是什么意思了

回答：
就是一个表。相当于 table other_table

php里字符串的连接符，将两个以上字符串连接起来