php - how to Check string present in database column? -
i have document table fields id
, sender_id
, receiver_id
, receiver_id
contains string value u12,u13,u14 logged in user , want find records in receiver_id
contains user_id
means user_id
u13
. how write query fetch records.
my query is:
$seldoc="select * documents sender_id='u".$_session['userid']."' or "u".$_session['userid']." in (receiver_id) order id desc";
but got error unknown column 'u13' in 'where clause'
you string concatenation messed up, should be: (further simplified)
$seldoc="select * documents 'u".$_session['userid']."' in (senderid,receiver_id) order id desc";
when statement above parsed, this:
select * documents 'uxx' in (senderid,receiver_id) // xx userid order id desc
as sidenote, query vulnerable sql injection
if value(s) of variables came outside. please take @ article below learn how prevent it. using preparedstatements
can rid of using single quotes around values.
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