I have to modify an existing table in a Oracle 10g DB with a few thousand records to add a surrogate autonumber key. One way that comes to my mind is to. Create a new sequence Create the id column, allowing null values Updating the id column with the sequence Alter table to add 'not null' and 'primary key' for the new id column. Aug 15, 2014 MS Access: Concatenated Key or Join Multiple Fields. Number, Date of Service and Physician Number. To do this, I usually concatenate the 3 fields in Excel then import to Access. Then I join the concatenated fields in a query. Even if you use an autonumber column as a 'surrogate' primary key there may well be other columns in the table. A key whose value has meaning to people. Most replacement keys are natural keys. Surrogate key. A key whose value has no meaning to people. A large number generated by the system, such as RecId, could be a surrogate key. A broad term that applies to primary keys and to alternate keys. It does not apply to foreign keys. Recommendations and examples for using the IDENTITY property to create surrogate keys on tables in Synapse SQL pool. What is a surrogate key. A surrogate key on a table is a column with a unique identifier for each row. The key is not generated from the table data. In a current database, the surrogate key can be the primary key, generated by the database management system and not derived from any application data in the database. The only significance of the surrogate key is to act as the primary key.
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Applies To: Microsoft Dynamics AX 2012 R3, Microsoft Dynamics AX 2012 R2, Microsoft Dynamics AX 2012 Feature Pack, Microsoft Dynamics AX 2012
This topic describes several terms and concepts of keys on data tables, as they apply to Microsoft Dynamics AX.
All keys are unique keys, meaning they disallow duplicate values and null values.
Terminology for Major Concepts of Keys
This section describes the terminology for keys that appear in property names in the AOT Properties window.
Primary Key
A primary key is one type of key. The other type of key is an alternate key. There is a maximum of one primary key per table, whereas a table can have several alternate keys. The primary key is usually the type of key that other tables, called child tables, refer to when a foreign key field in those other tables need a relational identifier.
Starting in Microsoft Dynamics AX 2012 the primary key for every new table is always enforced by an index that has exactly one field. The one field is usually an incremented number or a completely meaningless number that is generated by the system. For new tables the default is a primary key based on the RecId field. This is represented as the surrogate key in the user interface.
The following table describes the PrimaryIndex property and other major properties that are related to keys.
The following AOT image highlights the table properties that are related to keys.
Properties of the AtomicElement demonstration table
Alternate Key
A table can have several alternate keys. Any one alternate key can switch to being the primary key, if the alternate key is comprised of only one field.
A table can reference the alternate key of another table. However, it is more common for a table to reference the primary key of another table. As an option, an alternate key can be chosen as the ReplacementKey of a table.
In practice each alternate key relies on a unique index for its implementation and enforcement. However, a unique index alone does not make an alternate key. The AlternateKey property must be set to Yes to make a unique index be an alternate key.
The following table describes properties on the AOT node for an index.
The following image shows that the SymIdx index is an alternate key. Its AlternateKey property is set to Yes.
The properties of the SymIdx index
Relation
In Microsoft Dynamics AX a relation represents a foreign key. The following image shows that the AtomStIdx alternate key of the AtomicState parent table is referenced by this foreign key of the AtomicElement child table. The foreign key is comprised of the AtomicStateName field.
The properties for the AtomStFkyRel relation
The following image displays the AtomStIdx alternate key on the AtomicState table. The previous AtomStFkyRel relation references this alternate key.
The properties of the AtomStIdx alternate key and index
For more information about the properties of table relations, see Table Relation Properties.
ReplacementKey
A replacement key is an alternate key that the system can display on forms instead of a meaningless numeric primary key value. Each table can have a maximum of one replacement key.
The replacement key is chosen by setting the ReplacementKey property on the table. The drop-down list offers every alternate key as an available value. In the previous image of the AtomicElement table properties, the ReplacementKey property is SymIdx.
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Other Terminology for Keys
In Microsoft Dynamics AX, there are other terms that are used to describe table keys. These terms do not appear as property names in Microsoft Dynamics AX. These terms are described in the following table.
To Generate A Surrogate Key Microsoft Access Uses Number
See alsoTo Generate A Surrogate Key Microsoft Access Uses In Business
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