How do you alter the columns of the table? Think off NULL vs NOT NULL, or Char(1) –> Char(2)
Here are some think i used
--Update the Default value ALTER COLUMN tableName -- Set the type of the column to Char with a length of 1 ALTER columnName TYPE Char(1), -- Give the column a default value, in this case 'F' ALTER columnName SET DEFAULT = 'F'
Before you change from NULL to NOT NULL remember to update the field like this
-- Update the NULL fields to the new DEFAULT value UPDATE TBLPHONETYPES SET DELETED = 'F' WHERE DELETED is null;
To change the system-tables is not a good idea in general but for this i made a acception.
-- Change field from NULL to NOT NULL field UPDATE RDB$RELATION_FIELDS SET RDB$NULL_FLAG = 1 WHERE RDB$FIELD_NAME = 'DELETED' AND RDB$RELATION_NAME = 'TBLPHONETYPES'; -- Change field from NOT NULL to NULL field UPDATE RDB$RELATION_FIELDS SET RDB$NULL_FLAG = NULL WHERE RDB$FIELD_NAME = 'DELETED' AND RDB$RELATION_NAME = 'TBLPHONETYPES';