Databases
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    <p>The decision has to be taken in terms of what you want to do with your object. Since you are not including the option of storing a value, I will assume that you need the container to refer to an external object. If this is not a requirement, consider using what standard containers do: store a copy of the object.</p> <p>By using a reference you avoid having to check for NULL on creation (after creation both solutions share the same problem there: the external object might be destroyed, leaving you with a dangling reference and Undefined Behavior). The semantics of a reference are a little stronger, and anyone that reads the code will immediately understand: <em>This container is meant to hold a reference to this object for the whole lifetime of the container, the object lifetime is managed externally</em>.</p> <p>On the negative side of it, references are not resettable, once you set a reference it becomes an alias to the object, and you cannot reset it to refer to a different object. This means that a container that holds a reference will not be assignable by default as you cannot make it refer to a different object. Even if you provide a custom assignment operator, the reference cannot be changed and it will keep referring to the old object. You will not be able to provide member functions in the container to refer to a different object: once you set a reference, it is set forever.</p> <p>Pointers on the other hand, can be NULL, so you might want/need to check for validity of the pointer before use. They are resettable, and you can offer operations to have your container refer to a different object at any point, by default the container will be assignable. On the negative side, pointers can be used in different scenarios, so the semantics are not so clear. In particular, you will have to carefully document on the interface whether the container takes ownership of the pointer (and the responsibility to release the memory) or not. If you are going to handle ownership inside the container, then consider using a smart pointer (or else just make a copy and forget the original if you can, which will be less error prone).</p>
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Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

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