SYNOPSIS
perldoc DBIx::DBSchema::DBD
package DBIx::DBSchema::DBD::FooBase
use DBIx::DBSchema::DBD;
@ISA = qw(DBIx::DBSchema::DBD);
DESCRIPTION
Drivers should be named DBIx::DBSchema::DBD::DatabaseName, where DatabaseName is the same as the DBD:: driver for this database. Drivers should implement the following class methods:- columns CLASS DBI_DBH TABLE
- Given an active DBI database handle, return a listref of listrefs (see perllol), each containing six elements: column name, column type, nullability, column length, column default, and a field reserved for driver-specific use.
- column CLASS DBI_DBH TABLE COLUMN
- Same as columns above, except return the listref for a single column. You can inherit from DBIx::DBSchema::DBD to provide this function.
- primary_key CLASS DBI_DBH TABLE
- Given an active DBI database handle, return the primary key for the specified table.
- unique CLASS DBI_DBH TABLE
-
Deprecated method - see the indices method for new drivers.
Given an active DBI database handle, return a hashref of unique indices. The keys of the hashref are index names, and the values are arrayrefs which point a list of column names for each. See ``HASHES OF LISTS'' in perldsc and DBIx::DBSchema::Index.
- index CLASS DBI_DBH TABLE
-
Deprecated method - see the indices method for new drivers.
Given an active DBI database handle, return a hashref of (non-unique) indices. The keys of the hashref are index names, and the values are arrayrefs which point a list of column names for each. See ``HASHES OF LISTS'' in perldsc and DBIx::DBSchema::Index.
- indices CLASS DBI_DBH TABLE
-
Given an active DBI database handle, return a hashref of all indices, both
unique and non-unique. The keys of the hashref are index names, and the values
are again hashrefs with the following keys:
-
- name - Index name (redundant)
- using - Optional index method
- unique - Boolean indicating whether or not this is a unique index
- columns - List reference of column names (or expressions)
-
(See FS::DBIx::DBSchema::Index)
New drivers are advised to implement this method, and existing drivers are advised to (eventually) provide this method instead of index and unique.
For backwards-compatibility with current drivers, the base DBIx::DBSchema::DBD class provides an indices method which uses the old index and unique methods to provide this data.
-
- default_db_catalog
- Returns the default database catalog for the DBI table_info command. Inheriting from DBIx::DBSchema::DBD will provide the default empty string.
- default_db_schema
- Returns the default database schema for the DBI table_info command. Inheriting from DBIx::DBSchema::DBD will provide the default empty string.
- constraints CLASS DBI_DBH TABLE
-
Given an active DBI database handle, return the constraints (currently, foreign
keys) for the specified table, as a list of hash references.
Each hash reference has the following keys:
-
- constraint - contraint name
- columns - List refrence of column names
- table - Foreign taable name
- references - List reference of column names in foreign table
- match -
- on_delete -
- on_update -
-
- column_callback DBH TABLE_NAME COLUMN_OBJ
-
Optional callback for driver-specific overrides to SQL column definitions.
Should return a hash reference, empty for no action, or with one or more of the following keys defined:
effective_type - Optional type override used during column creation.
explicit_null - Set true to have the column definition declare NULL columns explicitly
effective_default - Optional default override used during column creation.
effective_local - Optional local override used during column creation.
- add_column_callback DBH TABLE_NAME COLUMN_OBJ
-
Optional callback for additional SQL statments to be called when adding columns
to an existing table.
Should return a hash reference, empty for no action, or with one or more of the following keys defined:
effective_type - Optional type override used during column creation.
effective_null - Optional nullability override used during column creation.
sql_after - Array reference of SQL statements to be executed after the column is added.
- alter_column_callback DBH TABLE_NAME OLD_COLUMN_OBJ NEW_COLUMN_OBJ
-
Optional callback for overriding the SQL statments to be called when altering
columns to an existing table.
Should return a hash reference, empty for no action, or with one or more of the following keys defined:
sql_alter - Alter SQL statement(s) for changing everything about a column. Specifying this overrides processing of individual changes (type, nullability, default, etc.).
sql_alter_type - Alter SQL statement(s) for changing type and length (there is no default).
sql_alter_null - Alter SQL statement(s) for changing nullability to be used instead of the default.
- column_value_needs_quoting COLUMN_OBJ
- Optional callback for determining if a column's default value require quoting. Returns true if it does, false otherwise.
TYPE MAPPING
You can define a %typemap array for your driver to map ``standard'' data types to database-specific types. For example, the MySQL TIMESTAMP field has non-standard auto-updating semantics; the MySQL DATETIME type is what other databases and the ODBC standard call TIMESTAMP, so one of the entries in the MySQL %typemap is:
'TIMESTAMP' => 'DATETIME',
Another example is the Pg %typemap which maps the standard types BLOB and LONG VARBINARY to the Pg-specific BYTEA:
'BLOB' => 'BYTEA', 'LONG VARBINARY' => 'BYTEA',
Make sure you use all uppercase-keys.