Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[42601]: - postgis

Question

I am new to postgresql/postgis and am unable to solve this problem. I have lat long values which I retrieve by the click event and split using
lonlat.split(",");
But when I pass them into the following query, I receive a syntax error.
$sql1=$conn->prepare("select id,ST_Contains(geom,GeomFromText(4326,'POINT(".$lon." ".$lat.")')) as yes_within from public.".$layername);
$sql1->execute();
Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[42601]: Syntax error: 7 ERROR: syntax error at end of input LINE 1: ...om,GeomFromText('POINT( )',4326)) as yes_within from public. ^' in C:\xampp\htdocs... Stack trace: #0 PDOStatement->execute() #1 {main} thrown in C:\xampp\htdocs... on line 22

Answer 1

From the error
Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[42601]: Syntax error: 7 ERROR: syntax error at end of input LINE 1: ...om,GeomFromText('POINT( )',4326)) as yes_within from public. ^' in C:\xampp\htdocs... Stack trace: #0 PDOStatement->execute() #1 {main} thrown in C:\xampp\htdocs... on line 22
That means that even though you think you're getting them from split, you're not getting them from split. You're concatenating an empty string. The problem isn't in PostgreSQL.
Aside from that, don't construct a point that way. Instead use,
ST_MakePoint(long,lat)::geography
Which creates a geography not a geometry and it does it without text-parsing.