DataSet/DataGrid/Null values

Question

Strange thing - when I bind a dataset to a datagrid and the
dataset column has null values, I cannot edit it. If I try to edit
the value, it just returns to the previous value when I press the
Enter key.
If all the rows start out with a non-null value, I can edit
them without any problem. Any thoughts?
TIA

Answer 1

Hello
While that is true for a unique index on columns where all values are null, it is not the case where one of the values is not null:
SQL> CREATE TABLE dt_test_nulls (id number, col1 varchar2(1))
  2  /
Table created.
SQL> CREATE UNIQUE INDEX dt_test_nulls_i1 on dt_test_nulls(id)
  2  /
Index created.
SQL> insert into dt_test_nulls values(null,'Y')
  2  /
1 row created.
SQL> insert into dt_test_nulls values(null,'N')
  2  /
1 row created.
SQL> create unique index dt_test_nulls_i2 on dt_test_nulls(id,col1)
  2  /
Index created.
SQL> insert into dt_test_nulls values(null,'N')
  2  /
insert into dt_test_nulls values(null,'N')
ERROR at line 1:
ORA-00001: unique constraint (BULK1.DT_TEST_NULLS_I2) violated
SQL> insert into dt_test_nulls values(null,null)
  2  /
1 row created.
SQL> insert into dt_test_nulls values(null,null)
  2  /
1 row created.I just thought it was worth pointing out.
HTH
David
Message was edited by:
david_tyler