if between and condition equivalent for dates

[Anonymous]

hi everyone,

I'm trying to add an expression for new column contains ok or null according to condition

here is my condition

if (tarih between '31.07.2016' and '31.08.2016', 'ok', 'null') but it didn't work.

*tarih refers column name contains dates

how can I make it

thanks

[m_woolf]

if(tarih>=date('31.07.2016' ) and tarih <=date('31.08.2016'),'ok','null')