Class PrimaryKey

Namespace

YndigoBlue.Velocity.Constraints

Assembly

YndigoBlue.Velocity.dll

Represents a primary key constraint that uniquely identifies each row in a table.

public class PrimaryKey : Constraint, IEquatable<Constraint>, IComparable<Constraint>

Inheritance

object

Constraint

PrimaryKey

Implements

IEquatable<Constraint>

IComparable<Constraint>

Remarks

A primary key constraint enforces uniqueness and non-null values for one or more columns. Each table can have only one primary key, which can be either single-column or composite (multiple columns).

Examples

// Define a table with a single-column primary key
var table = new Table(schema, "users");
table.AddColumn("id", DataType.Integer, autoIncrement: true);
table.AddColumn("username", DataType.VarChar, 50);
table.AddColumn("email", DataType.VarChar, 100);

// Primary key is automatically created on 'id' column when autoIncrement is true

// Or create a composite primary key manually
var orderItemsTable = new Table(schema, "order_items");
orderItemsTable.AddColumn("order_id", DataType.Integer);
orderItemsTable.AddColumn("product_id", DataType.Integer);
orderItemsTable.AddColumn("quantity", DataType.Integer);

// Composite primary key on both order_id and product_id
var pk = new PrimaryKey("pk_order_items", schema.Name, "order_items",
    new[] { "order_id", "product_id" });

Properties

Columns

Gets or sets the collection of column names that make up the primary key.

ConstraintType

Gets the constraint type as PrimaryKey.

IsComposite

Gets whether this is a composite primary key (spanning multiple columns).

Methods

IsEqual(Constraint)

Determines whether this constraint is equal to another constraint based on their properties.