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Sorting and saving values based on unique entries
01-08-2014
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DBSchema::DBD(3pm) User Contributed Perl Documentation DBSchema::DBD(3pm) NAME
DBIx::DBSchema::DBD - DBIx::DBSchema Driver Writer's Guide and Base Class 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. 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. AUTHOR
Ivan Kohler <ivan-dbix-dbschema@420.am> COPYRIGHT
Copyright (c) 2000-2005 Ivan Kohler Copyright (c) 2007-2010 Freeside Internet Services, Inc. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. BUGS
SEE ALSO
DBIx::DBSchema, DBIx::DBSchema::DBD::mysql, DBIx::DBSchema::DBD::Pg, DBIx::DBSchema::Index, DBI, DBI::DBD, perllol, "HASHES OF LISTS" in perldsc perl v5.14.2 2010-01-09 DBSchema::DBD(3pm)