How to add " to a String

Julian

Hello, I need to add "" to a String and it do not considers. For example:

 QString list;
  list.append("CREATE TABLE IF NOT EXISTS ");
   list.push_back(ui->lineEdit_interseccion->text());  //this is the tabla name

 list.push_back("("
                    "a TEXT primary key,"
                    "j TEXT"
                    ");");
    ui->label->setText(list);

And with that seTex I get:

CREATE TABLE IF NOT EXISTS Soler y Sarabia (a TEXT primary key, j TEXT)

So as you can see there is not "" between ().

How can I put it?

mostefa

Hi @Julian

let's say you have :

QString tabla = "yourString";

if you want to add " to your string you can do someting like this :

tabla.push_back("\"");

The result will be then :

yourString"

The key is to have \" instead of " , \ allow you actullay to escape the character "

Hope this can help !

VRonin

You can either escape (i.e. add a \ before) the " or use raw string literals

"I have a \" in the Middle"
R"**(I have a " in the Middle)**"

P.S.

list.append("CREATE TABLE IF NOT EXISTS ");
   list.push_back(ui->lineEdit_interseccion->text());  //this is the tabla name

This is a MAJOR liability to your database, see https://www.w3schools.com/sql/sql_injection.asp

Julian

Thanks! I have a problem here

 QString consulta;
  consulta.append("CREATE TABLE IF NOT EXISTS ");
    consulta.push_back(ui->lineEdit_interseccion->text()  ); //this it's the table name.

then I do


    consulta.push_back(" ( \" a TEXT primary key, \"  \"j TEXT\" \");");

and there is the problem.

alt text

jsulm

@Julian You should really read about escaping characters in C/C++.
You're escaping first " in second and third line ("j TEXT"...).
You should not because it indicates the beginning of a string!
It should be:

"\"j TEXT"
"\")");

J.Hilk

@Julian

The problem now is that you span your string over multiple rows in QtCreator. The new Chars in the new line need their own " to mark them as part of the previous string.

//Correct MultiLineString
QString s = "Line1 "
                      "\"Line2\" "
                      "Line3 "
//Results in
//s =  Line1 "Line2" Line3