“ where子句”中的未知列“…”

Question

I'm having this problem with a specific task:

SELECT radnik.*, nalog.prioritetNalog FROM radnik
INNER JOIN nalog ON radnik.sifRadnik=nalog.sifRadnik
WHERE kvar.nazivKvar ="Zamjena klipa";

Results in:

Error Code: 1054
Unknown column 'kvar.nazivKvar' in 'where clause'

It says this, but the column and datatable exist

https://i.stack.imgur.com/mQZt4.jpg

Answer 1

try this syntax :

SELECT column1, column2....columnN
FROM   table_name1 t1, table_name2 t2
on t1.id = t2.id
WHERE  CONDITION;

Example :

SELECT radnik.*, nalog.prioritetNalog 
FROM radni INNER JOIN nalog 
ON radnik.sifRadnik=nalog.sifRadnik
WHERE table_name.column_name ="Zamjena klipa";

Answer 2

You need an additional JOIN :

SELECT r.*, n.prioritetNalog
FROM radnik r INNER JOIN
     nalog n
     ON r.sifRadnik = n.sifRadnik INNER JOIN
     kvar k
     ON k.sifkvar = n.sifkvar
WHERE k.nazivKvar = 'Zamjena klipa';

You can only reference columns in a query that are defined in the FROM clause.

Answer 3

I was missing one more join, thanks for the help

SELECT radnik.*, nalog.prioritetNalog FROM radnik
inner JOIN nalog ON radnik.sifRadnik=nalog.sifRadnik
inner join kvar on nalog.sifKvar=kvar.sifKvar 
WHERE kvar.nazivKvar ="Zamjena klipa";