Alzabo, Alzabo::Create, and Alzabo::Runtime

  use Alzabo::Runtime qw( schema1 schema2 schema3 );

Alzabo::MethodMaker

  use Alzabo::MethodMaker ( schema => 'some_schema',
                            # Root for new packages
                            class_root => 'My::Data',
                            # Make all possible methods
                            all => 1 );

This will make convenience methods for such things as getting table and column objects, following various types of foreign keys, and getting data from row objects.

Retrieving data

This object allows you to connect to the database. It contains several data retrieval methods including "join".

• load_from_file

  Load an existing schema object from disk. Returns a new schema object.

• set_user ($user)

  Set the username to be used when connecting to the database.

• set_password ($password)

  Set the password to be used when connecting to the database.

• set_host ($host)

  Set the host to be used when connecting to the database.

• connect (%params)

  Connect to the RDBMS. This will use the previously set username/password/host, though these can be overridden by the %params given to the call.

  Important: This method must be called before any data retrieval is attempted.

• join

  Fetch rows from one or more tables based on a table join. Returns either a "Alzabo::Runtime::RowCursor" or "Alzabo::Runtime::JoinCursor" object.

• function/select

  Allows you to execute arbitrary column aggregate SQL functions such as "AVG" or "MAX" with a multi-table join.

• table ($name)

  Returns an "Alzabo::Runtime::Table" object. This is important because most of the row fetching operations are table object methods.

Alzabo::Runtime::Table

Objects in this class have methods allowing you to insert new rows as well as retrieving exist data in the form of "Alzabo::Runtime::Row" or "Alzabo::Runtime::RowCursor" objects.

All methods that return a single row return an "Alzabo::Runtime::Row" object.

All methods that return multiple rows return an "Alzabo::Runtime::RowCursor" object.

All methods that return rows can be given the "no_cache" parameter, which ensures that the row(s) returned will not be cached. Rows obtained in this manner should not be updated or deleted, as this will play havoc with the caching system. See the "Alzabo::Runtime::Row" documentation for more details.

All methods that return multiple rows in the form of a cursor object can take an "order_by" parameter. See the "Alzabo::Runtime::Table" documentation for more details.

• insert

  Insert a new row and return it.

• row_by_pk

  Returns the row identified by the primary key give.

• rows_where

  Retrieves a set of rows based on a where clause. Please see the method documentation for details on how where clauses are constructed.

• all_rows

  Retrieves all the rows in the table.

• function/select

  Allows you to execute arbitrary column aggregate SQL functions such as "AVG" or "MAX".

• potential_row

  Make a new "Alzabo::Runtime::Row" in the "potential" state.

Alzabo::Runtime::Row

Objects in this class represent a single row of data. You can retrieve the actual column values from it, update it, or delete it.

• select (@list_of_column_names)

  Given a list of column names, this method returns the values for those columns.

• update (%hash_of_columns_and_values)

  Given a hash of columns and values, this method will update the database and the object to match those values.

• delete

  Deletes the row from the database. Further attempts to retrieve data from this row will throw an exception.

• rows_by_foreign_key

  Given a foreign key object from the row's table to another table, returns either an "Alzabo::Runtime::Row" object or an "Alzabo::Runtime::RowCursor" object for the row(s) in the table to which the relationship exists, based on the value of the relevant column(s) in the current row.

  This method can also take a "no_cache" and/or "order_by" parameter.

Alzabo::Runtime::RowCursor

Objects in this class are used to return multiple rows as a cursor, rather than as a list. This is much more efficient, at the expense of a few extra lines in your code.

• next

  Returns the next "Alzabo::Runtime::Row" object, or undef if there are no more.

• all_rows

  Returns a list of all the remaining "Alzabo::Runtime::Row" objects, or an empty list if there are no more.

Creating/removing a schema

This object represents a schema, and contains one or more table objects. It is only used when creating or altering a schema, as opposed to when fetching data. Data manipulation is done via the "Alzabo::Runtime::*" classes.

• reverse_engineer

  Connect to a database and reverse engineer a schema. Returns a new schema object.

• load_from_file

  Load an existing schema object from disk. Returns a new schema object.

• create

  If the schema has not yet been instantiated in an RDBMS, this method will instantiate the schema. If it has been previously instantiated, it will bring the schema in the RDBMS into sync with its object representation (altering tables/columns, etc.) Where possible, exist data will be preserved.

• make_sql

  Returns an array, each element of which is a SQL statement. The SQL is either the SQL to create the schema from scratch or the SQL needed to update the RDBMS to match the current object. See the "create" method for more details.

• drop

  Drop the database from the RDBMS where it was created. Does not remove the schema object itself from disk.

• delete

  Delete the schema object files from disk. Does not drop the database from the RDBMS.