Key type definitions

Key type definitions allow you to specify the type of key and the names of the fields within the key. There may be more than one field in one key. A key with multiple fields is called a concatenated key.

Key Type Description
Primary No fields in the key can be null. The value of the complete key cannot be null and must be unique in the index. A table can have at most one primary key.
Unique At least one field in the key must not be null. The value of the complete key must be unique in the index.
No Nulls At least one field in the key must not be null.
No Duplicates The value of the complete key must be unique in the index or the values of all fields must be null.
Nulls & Duplicates All fields can be null. The complete key value can be in the index more than once.
IR key The fields in the key are indexed by IR Expert. Only one IR key can be used per dbdict record or IR searches on that file do not work. You can concatenate several fields in an IR key.

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