Package edu.caltech.nanodb.relations

This package contains the basic data-types for representing relations in NanoDB. Relations can be many different things - tables, views, external tables, or results of subqueries in a particular SQL query, for example. All of the common classes are in this package.

Type Information

One of the major aspects of this package is the collection of classes that represent type information in the database. The classes are as follows:

• Data-types are defined by the SQLDataType enumeration, which contains both the enumerated types and predefined type-ID byte-values.
• Column-types are defined by the ColumnType class, which contains the SQL data-type for the column (using the SQLDataType enum), and any additional information about the column's type that might need to be specified. For example, a CHAR(100) column has a base-type of SQLDataType.CHAR, but it must also specify its length as 100 characters. This additional information is also included in the ColumnType class.

Interface Summary

Interface	Description
Tuple	This interface provides the operations that can be performed with a tuple.

Class Summary

Class	Description
ColumnInfo	Basic information about a table column, including its name and SQL type.
ColumnRefs	This class represents a set of columns in a schema by specifying the indexes of the columns in the set.
ColumnType	The type of a single column in a relation.
DatabaseConstraintEnforcer	This class enforces all database constraints on the database schema, including NOT NULL constraints, primary key/unique constraints, and foreign key constraints.
ForeignKeyColumnRefs	This class represents a foreign key constraint between two tables in the database.
IndexColumnRefs	This class records that there is an index built on a particular set of columns.
KeyColumnRefs	This class represents a primary key or other unique key, specifying the indexes of the columns in the key.
Schema	A schema is an ordered collection of column names and associated types.
Schema.IndexedColumnInfo	This helper class is used for the internal hashed column structure, so that we can do fast lookups based on table names and column names.
TableInfo	This class represents a single table in the database, including the table's name, and the tuple file that holds the table's data.
TableUtils	Created by donnie on 7/16/17.
TupleUtils

Enum Summary

Enum	Description
ForeignKeyValueChangeOption	An enumeration specifying the options allowed for ON DELETE and ON UPDATE actions for foreign keys.
JoinType	An enumeration specifying the different types of join operation.
SQLDataType	An enumeration of the SQL data-types that are supported by NanoDB.
TableConstraintType	An enumeration specifying the constraint types allowed on tables.

Exception Summary

Exception	Description
ConstraintViolationException	This exception is used to signal when a database constraint is violated.
SchemaNameException	This exception is thrown when there are any schema name issues, such as duplicate column names, duplicate table names, ambiguous or invalid names, and so forth.