Question

How do I escape a dot in insert query?

   insert into './$x/.' () lues( );

How to escape the dot before $x and after $x, I tried the above but did not work.

Answer 1

Use back slash, not forward slash.

\
also, you need to escape things by placing the escape character BEFORE the thing it’s escaping.

E.g.

"INSERT INTO `\$my_table` VALUES(NULL,$asdf,$jkl)"

Ok, but in your case, try this:

insert into `.$x.` () lues( );

Those are not ‘ but `

That is the backtick character. Same key as ~ on U.S. keyboards.

Concatenating a variable and a string:

$query = 'INSERT INTO `' . $my_table . '` VALUES(NULL,asdf,' . $jkl . ')";

But inside of double quotes "" you can just put the variable names into the string:

$query = 'INSERT INTO `$my_table` VALUES(NULL,asdf,$jkl )";

(Both of the above result in the exact same string being assigned to variable $query)

Take a look at the PHP page on strings

You can see sections on single quote, double quote, and others that will blow your mind (HEREDOC).

Important: also check out ‘parameterized queries’.