Package org.datanucleus.store.rdbms.key

Class PrimaryKey

  • public class PrimaryKey
extends Object
    Representation of the primary key of a table. TODO MariaDB apparently allows "ALTER TABLE ADD CONSTRAINT PRIMARY KEY (col1 ASC, col2 DESC)" not that many others do but we don't allow that here, would need to extend ColumnOrderedKey for that, plus update to MySQL Adapter

    • Field Detail

      • name

        protected String name
        Name of the key.

      • table

        protected Table table
        Table that the key applies to.

      • columns

        protected List<Column> columns
        Columns that the key relates to.

    • Constructor Detail

      • PrimaryKey

        public PrimaryKey​(Table table)
        Creates a primary key. A default name of the primary key is created by the constructor. This name can be overwritten.
        Parameters:
        table - Table that this is the PK for

    • Method Detail

      • equals

        public boolean equals​(Object obj)
        Equality operator.
        Parameters:
        obj - Object to compare against
        Returns:
        Whether they are equal.

      • hashCode

        public int hashCode()
        Hashcode operator.
        Returns:
        The hashcode

      • toString

        public String toString()
        Stringifier method. Generates a form of the PK ready to be used in a DDL statement. e.g 
        PRIMARY KEY (col1,col2)
        Overrides:
        toString in class Object
        Returns:
        The string form of this object. Ready to be used in a DDL statement.

      • setName

        public void setName​(String name)
        Mutator for the key name.
        Parameters:
        name - The key name

      • getName

        public String getName()
        Accessor for the key name.
        Returns:
        Key name

      • getTable

        public Table getTable()
        Accessor for the table
        Returns:
        table

      • getColumns

        public List<Column> getColumns()
        Accessor for the columns that the key relates to.
        Returns:
        the List of columns.

      • getColumnList

        public String getColumnList()
        Accessor for the column list
        Returns:
        The column list

      • getNumberOfColumns

        public int getNumberOfColumns()
        Accessor for the number of columns.
        Returns:
        The number of columns.

      • addColumn

        public void addColumn​(Column col)
        Class to add a column to the key
        Parameters:
        col - The column to add

      • setColumn

        public void setColumn​(int seq,
                      Column col)
        Sets a column in a specified position seq for this index.
        Parameters:
        seq - the specified position for the col
        col - the Column

      • assertSameDatastoreObject

        protected void assertSameDatastoreObject​(Column col)
        Utility to assert if the column is for a different table.
        Parameters:
        col - The column to compare with

      • setListMinimumSize

        protected static void setListMinimumSize​(List list,
                                         int size)

      • getColumnList

        public static String getColumnList​(List<Column> cols)
        Method to return the list of columns which the key applies to.
        Parameters:
        cols - The columns.
        Returns:
        The column list.