I am using https://github.com/buggins/ddbc

string query_string = (`SELECT user, password FROM otest.myusers where user LIKE ` ~ `'%` ~ request["username"].to!string ~ `%';`);
        auto rs = db.stmt.executeQuery(query_string);

        string dbpassword;
        string dbuser;

        while (rs.next())
        {
            dbuser = rs.getString(1);
            dbpassword = rs.getString(2);
            writeln(dbuser);
            writeln("Place seems unreachable"); // if SQL result is empty
...

How I can check if SQL request returned empty result?

On 11.12.2015 22:05, Suliman wrote:
> I am using https://github.com/buggins/ddbc
>
> string query_string = (`SELECT user, password FROM otest.myusers where
> user LIKE ` ~ `'%` ~ request["username"].to!string ~ `%';`);

Don't piece queries together without escaping the dynamic parts. Imagine what happens when the user enters an apostrophe in the username field.

Also, are you using LIKE when authenticating the user? O_O

> How I can check if SQL request returned empty result?

When the result is empty, then rs.next() returns false on the first call, I presume.

>> string query_string = (`SELECT user, password FROM otest.myusers where
>> user LIKE ` ~ `'%` ~ request["username"].to!string ~ `%';`);
>
> Don't piece queries together without escaping the dynamic parts. Imagine what happens when the user enters an apostrophe in the username field.

Do you mean to wrap:
 request["username"].to!string
in quotes?


> Also, are you using LIKE when authenticating the user? O_O

Yes, my issue :)


>> How I can check if SQL request returned empty result?
>
> When the result is empty, then rs.next() returns false on the first call, I presume.

SO I can wrap it in `if`? Like: `if(rs.next())` ?

it's seems that next block is execute even if is rs.next() is false:

writeln("rs.next()-->", rs.next());
if(!rs.next()) //if user do not in DB
{
// is execute even if rs.next() is false
writeln("Executed, but rs.nst was set to false");
}

The output:
> rs.next()-->false
> Executed, but rs.nst was set to false

Why?

12.12.2015 13:28, Suliman пишет:
> it's seems that next block is execute even if is rs.next() is false:
>
> writeln("rs.next()-->", rs.next());
> if(!rs.next()) //if user do not in DB
> {
> // is execute even if rs.next() is false
> writeln("Executed, but rs.nst was set to false");
> }
>
> The output:
>> rs.next()-->false
>> Executed, but rs.nst was set to false
>
> Why?
>
>

That's right, because you have `if(!rs.next())`. If you change this to `if(rs.next())` this code block won't be executed.

On Saturday, 12 December 2015 at 10:36:12 UTC, drug wrote:
> 12.12.2015 13:28, Suliman пишет:
>> it's seems that next block is execute even if is rs.next() is false:
>>
>> writeln("rs.next()-->", rs.next());
>> if(!rs.next()) //if user do not in DB
>> {
>> // is execute even if rs.next() is false
>> writeln("Executed, but rs.nst was set to false");
>> }
>>
>> The output:
>>> rs.next()-->false
>>> Executed, but rs.nst was set to false
>>
>> Why?
>>
>>
>
> That's right, because you have `if(!rs.next())`. If you change this to `if(rs.next())` this code block won't be executed.

http://img.ctrlv.in/img/15/12/12/566c03c0657df.png

Oh sorry! I used wrong host! All ok!

On Saturday, 12 December 2015 at 11:31:18 UTC, Suliman wrote:
> Oh sorry! I used wrong host! All ok!

Yes, there was issue with host name, but it's do not solve problem. Second DB have same fields and I still getting false instead moving into while loop

On Saturday, 12 December 2015 at 11:53:51 UTC, Suliman wrote:
> On Saturday, 12 December 2015 at 11:31:18 UTC, Suliman wrote:
>> Oh sorry! I used wrong host! All ok!
>
> Yes, there was issue with host name, but it's do not solve problem. Second DB have same fields and I still getting false instead moving into while loop

It's look like it do `next` step before return something.
So if in DB 1 value it will work like:
do step
if no value after it --> return false
if yes --> return true

but I need any way to check if first value in DB is exists. Any suggestion?

On Saturday, 12 December 2015 at 12:06:21 UTC, Suliman wrote:
> On Saturday, 12 December 2015 at 11:53:51 UTC, Suliman wrote:
>> On Saturday, 12 December 2015 at 11:31:18 UTC, Suliman wrote:
>>> Oh sorry! I used wrong host! All ok!
>>
>> Yes, there was issue with host name, but it's do not solve problem. Second DB have same fields and I still getting false instead moving into while loop
>
> It's look like it do `next` step before return something.
> So if in DB 1 value it will work like:
> do step
> if no value after it --> return false
> if yes --> return true
>
> but I need any way to check if first value in DB is exists. Any suggestion?

If you expect to have single or zero rows in result, use
if (rs.next()) {
            dbuser = rs.getString(1);
            dbpassword = rs.getString(2);
            writeln(dbuser);
} else {
            writeln("user not found");
}