Package edu.caltech.nanodb.relations

Class ColumnInfo

  • All Implemented Interfaces:
    java.io.Serializable
    public class ColumnInfo
extends java.lang.Object
implements java.io.Serializable
    Basic information about a table column, including its name and SQL type. Constraints, even "NOT NULL" constraints, appear at the table level, since some constraints can involve multiple columns.
    See Also:
    Serialized Form
    Design Note:
    (donnie) Right now this class is immutable, which I tend to think is a good idea for schema information. So far there aren't any classes that really require the ability to mutate column-info objects, although the biggest candidates are the TupleLiteral class and the ProjectNode class, which sometimes need to generate names for their results.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private java.lang.String name
      The name of the attribute.
      private java.lang.String tableName
      An optional table-name for the attribute, in cases where a join or Cartesian product generates a result with duplicate attribute-names.
      private ColumnType type
      The type information for the column.

    • Constructor Summary

      Constructors 
      Constructor Description
      ColumnInfo​(ColumnType type)
      Construct a new column-info object for a column, specifying the type of the column.
      ColumnInfo​(java.lang.String name, ColumnType type)
      Construct a new column-info object for a column, specifying the attribute name and type of the column.
      ColumnInfo​(java.lang.String name, java.lang.String tableName, ColumnType type)
      Construct a new column-info object for a column, specifying the attribute name, table name, and type of the column.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean equals​(java.lang.Object obj)  
      ColumnName getColumnName()
      Returns a ColumnName object representing the name of this column.
      java.lang.String getName()
      Returns the name of the attribute.
      java.lang.String getTableName()
      Returns the table-name of the attribute.
      ColumnType getType()
      Returns the type of the attribute.
      int hashCode()  
      java.lang.String toString()
      Returns a string representation of the column-info.

      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait

    • Field Detail

      • name

        private java.lang.String name
        The name of the attribute.

      • tableName

        private java.lang.String tableName
        An optional table-name for the attribute, in cases where a join or Cartesian product generates a result with duplicate attribute-names. In most cases it is expected that this table-name will be null.

      • type

        private ColumnType type
        The type information for the column.

    • Constructor Detail

      • ColumnInfo

        public ColumnInfo​(java.lang.String name,
                  java.lang.String tableName,
                  ColumnType type)
        Construct a new column-info object for a column, specifying the attribute name, table name, and type of the column.
        Parameters:
        name - the attribute name, or null if unspecified
        tableName - the table name, or null if unspecified
        type - the type of the column

      • ColumnInfo

        public ColumnInfo​(java.lang.String name,
                  ColumnType type)
        Construct a new column-info object for a column, specifying the attribute name and type of the column. The table name is unspecified.
        Parameters:
        name - the attribute name, or null if unspecified
        type - the type of the column

      • ColumnInfo

        public ColumnInfo​(ColumnType type)
        Construct a new column-info object for a column, specifying the type of the column. The attribute name and table name are unspecified.
        Parameters:
        type - the type of the column

    • Method Detail

      • getName

        public java.lang.String getName()
        Returns the name of the attribute.
        Returns:
        the name of the attribute

      • getTableName

        public java.lang.String getTableName()
        Returns the table-name of the attribute.
        Returns:
        the table-name of the attribute

      • getColumnName

        public ColumnName getColumnName()
        Returns a ColumnName object representing the name of this column.
        Returns:
        a column-name object for this column

      • getType

        public ColumnType getType()
        Returns the type of the attribute.
        Returns:
        the type of the attribute

      • equals

        public boolean equals​(java.lang.Object obj)
        Overrides:
        equals in class java.lang.Object

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object

      • toString

        public java.lang.String toString()
        Returns a string representation of the column-info.
        Overrides:
        toString in class java.lang.Object