oracle11g - SQL Error Missing Right Parenthesis -

oracle11g - SQL Error Missing Right Parenthesis -

i new sql , running on command prompt orcale 11g installed

create table transaction( transaction_id number primary key, account_no number foreign key references account_creation(account_no), transaction_date date, amount number, transaction_type varchar2(5) check( transaction_type=’c’ or transaction_type=’d’), current_balance number, branch_code varchar2(10) );

i error907 @ line 4 saying missing right parenthesis doing wrong?

if line correct:

transaction_type varchar2(5) check( transaction_type=’c’ or transaction_type=’d’),

then have wrong single quotes in line. seek this:

transaction_type varchar2(5) check( transaction_type = 'c' or transaction_type = 'd'),

or, improve yet:

transaction_type varchar2(5) check( transaction_type in ('c', 'd')),

sql oracle11g