Mysql查询似乎混淆了

Question

$q=2013 

$sql="SELECT * FROM vip_sales WHERE type = 'vecka' and date >= '"$q ."-01-01' and date <= '"$q ."-01-31' "; 

$result = mysql_query($sql, $con); 
$janw = mysql_num_rows($result); 

$sql="SELECT * FROM vip_sales WHERE type = 'manad' and date >= '"$q ."-01-01' and date <= '"$q ."-01-31' "; 
$result = mysql_query($sql, $con); 
$janm = mysql_num_rows($result); 

$sql="SELECT * FROM vip_sales WHERE type = 'ar' and date >= '"$q ."-01-01' and date <= '"$q ."-01-31' "; 

这行''$ q。“ - 01-01'is it =”2013-01-01“？

我的，我用来建立代码程序与说，有一个错误，但我不能找到我的PHPadmin

$sql="SELECT * FROM vip_sales WHERE type = 'ar' and date >= '2013-01-01' and date <= '2013-01-31' "; 

我测试了这个任何错误，它工作正常。我只是想确保这是正确的使用线。 Cuse当我测试

$sql="SELECT * FROM vip_sales WHERE type = 'ar' and date >= '"2013 ."-01-01' and date <= '"2013 ."-01-31' "; 

它dident工作。我可能会混淆“和”。

感谢所有帮助

Answer 1

试试这个

$sql="SELECT * FROM vip_sales WHERE type = 'vecka' and date >= '".$q."-01-01' and date <= '".$q."-01-31'"; 

它会给你下面的SQL查询：

SELECT * FROM vip_sales WHERE type = 'vecka' and date >= '2013-01-01' and date <= '2013-01-31' 

Answer 2

我觉得雅需要另一个点。当您连接，如果您有任何字符串，任何变量之间的时间段。在这里阅读更多http://php.net/manual/en/language.operators.string.php

"SELECT * FROM vip_sales WHERE type = 'manad' and date >= '" . $q ."-01-01' and date <= '" . $q ."-01-31' ";