Error: invalid input syntax for integer: ""

Question

I have this table `tbl_buku`: ``` id_buku judul_buku tahun_buku 1 Bioogi 2010 2 Fisika 2010 3 Informatika 2012 4 Kimia 2012 ``` I use query like this, but I am getting an error: ``` select case when t1.tahun_buku=t2.tahun_buku then '' else t1.tahun_buku end tahun_buku,t1.judul_buku from tbl_buku t1 left join tbl_buku t2 on t1.id_buku-1=t2.id_buku; ``` I want to show table like this: ``` tahun_buku judul_buku 2010 Biologi Fisika 2012 Informatika Kimia ``` How to achieve this?

Accepted Answer

I think the problem in your query is that `tahun_buku` is of `datatype int` and you are trying to select an empty `string` (`''`).

You have to workarounds:

Change `tahun_buku` to be `varchar` (2010,2012..will be consider as strings I dont know if it is ok)

Set:

```
select case when t1.tahun_buku=t2.tahun_buku then null else t1.tahun_buku end tahun_buku,t1.judul_buku
from tbl_buku t1 left join tbl_buku t2
on t1.id_buku-1=t2.id_buku;
```

Error: invalid input syntax for integer: ""

Solution

Problem