使用$ _SESSION Var进行查询时出错

$sth7 = $pdo7->prepare("SELECT usr FROM tz_members WHERE id = $_SESSION['id'];");

is giving me this error:

syntax error, unexpected T_ENCAPSED_AND_WHITESPACE, expecting T_STRING or T_VARIABLE or T_NUM_STRING

How do I fix this?

Try:

$sth7 = $pdo7->prepare("SELECT usr FROM tz_members WHERE id = " . $_SESSION['id'] . ";");

Here's a link to the exact same problem with a solution.