I am trying to generate a query like: 

```
select ifnull(t1.name, ‘default’) as name
from tab1 as t1
left join tab2 as t2 
 on t1.id=t2.id and t2.code=“someValue”

```

I wrote this in knex:

```
var query = knex().from(’tab1’).join(’tab2', function() {

    this.on('tab1.id', '=', 'tab2.id').andOn('tab2.code', '=', 'someValue')
}, 

‘left')
.column([

knex.raw(‘IFNULL(tab1.name, "no name") as name')

]);

```

This does not execute as it treats 'someValue' as a column.
How can I apply 'and' condition in this case?