/ 
XAO-FS-1.03
River stage one • 5 direct dependents • 5 total dependents
/ XAO::DO::FS::Glue::MySQL_DBI

NAME

XAO::DO::FS::Glue::MySQL_DBI - DBD::mysql driver for XAO::FS

SYNOPSIS

Should not be used directly.

DESCRIPTION

This module implements some functionality required by FS::Glue in MySQL specific way. The module uses DBD/DBI interface; whenever possible it is recommended to use direct MySQL module that works directly with database without DBD/DBI layer in between.

This is the lowest level XAO::FS knows about. Underneath of it are DBD::mysql, DBI, database itself, operationg system, hardware, atoms, protons, gluons and so on and on and on.. The level might be not so low if we look at it this way.

METHODS

new ($%)

Creates new instance of the driver connected to the given database using DSN, user and password.

Example:

my $driver=XAO::Objects->new(objname => 'FS::Glue::MySQL',
                             dsn => 'DBI:MySQL_DBI:dbname',
                             user => 'username',
                             password => '123123123');
add_field_integer ($$$$)

Adds new integer field to the given table. First parameter is table name, then field name, then index flag, then unique flag, then minimal value and then maximum value.

Note: Indexes only work with MySQL 3.23 and later.

add_field_real ($$;$$)

Adds new real field to the given table. First parameter is table name, then field name, then index flag, then unique flag, then optional minimal value and then optional maximum value.

Note: Indexes only work with MySQL 3.23 and later.

add_field_text ($$$$$)

Adds new text field to the given table. First is table name, then field name, then index flag, then unique flag, maximum length and 'connected' flag. Depending on maximum length it will create CHAR, TEXT, MEDIUMTEXT or LONGTEXT.

'Connected' flag must be set if that table holds elements deeper into the tree then the top level.

Note: Modifiers 'index' and 'unique' only work with MySQL 3.23 and later.

add_table ($$$)

Creates new empty table with unique_id, key and optionally connector fields.

delete_row ($$)

Deletes a row from the given name and unique_id.

disconnect ()

Permanently disconnects driver from database. Normally perl's garbage collector will do that for you.

drop_field ($$$$$)

Drops the given field from the given table in the database. Whatever content was in that field is lost irrevocably.

If index, unique and connected flags are given then it first will drop the appropriate index.

drop_table ($)

Drops the given table with all its data. Whatever content was in that table before is lost irrevocably.

initialize_database ($)

Removes all data from all tables and creates minimal tables that support objects database.

list_keys ($$$$)

Returns a reference to an array containing all possible values of a given field (list key) in the given table. If connector is given - then it is used in select too.

load_structure ()

Loads Global_Fields and Global_Classes tables into internal hash for use in Glue.

Returns the hash reference.

TODO: This should be changed so that data types would not be hard-coded here. Probably a reference to a subroutine that will parse and store them would do the job?

mangle_field_name ($)

Adds underscore to the end of field name to avoid problems with reserved words. Could do something else in other drivers, do not count on the fact that there would be underscore at the end.

retrieve_fields ($$$@)

Retrieves individual fields from the given table by unique ID of the row. Always returns array reference even if there is just one field in it.

search (\%query)

performs a search on the given query and returns a reference to an array of arrays containing search results. Query hash is as prepared by _build_search_query() in the Glue.

search_clause_wq ($field $string)

Returns database specific syntax for REGEX matching a complete word if database supports it or undef otherwise. For MySQL returns REGEXP clause.

search_clause_ws ($field $string)

Returns database specific syntax for REGEX matching the beginning of a word if database supports it or undef otherwise. For MySQL returns REGEXP clause.

setup_dictionary ($$$)

Supposed to set up dictionary tables if required. For MySQL driver it does nothing as all dictionaries are stored in the same table currently and this table is created when initial database layout is created.

store_row ($$$$$$$)

Stores complete row of data into the given table. New name is generated in the given key field if there is no name given.

Example:

$self->_driver->store_row($table,
                          $key_name,$key_value,
                          $conn_name,$conn_value,
                          \%row);

Connector name and connector value are optional if this list is directly underneath of Global.

unique_id ($$$$$)

Looks up row unique ID by given key name and value (required) and connector name and value (optional for top level lists).

update_dictionary ($table $uid $name $value)

Updates dictionary for the given field. Dictionary is supported by two tables Global_Dictionary and Global_Backrefs. The first table is dictionary itself, while the second holds references that allow to delete/modify records in the dictionary quicker.

Here is an example content of Global_Dictionary with two names ('John Silver' and 'John Doe') encoded. It assumes that unique_id's of rows that holds `John Silver' and 'John Doe' in Customers table are 15 and 25 respectfully.

| unique_id | table_name | field_name | strip  |  ids  |
+-----------+------------+------------+--------+-------+
|         1 | Customers  | name       | john   | 15,25 |
|         2 | Customers  | name       | silver | 15    |
|         3 | Customers  | name       | doe    | 25    |

Structure of Global_Backrefs for the same data:

| unique_id | table_name | table_uid | field_name | ids |
+-----------+------------+-----------+------------+-----+
|         1 | Customers  | 15        | name       | 1,2 |
|         2 | Customers  | 25        | name       | 1,3 |
update_field ($$$$) {

Stores new value into single data field. Example:

$self->_driver->update_field($table,$unique_id,$name,$value);
update_key ($$$$) {

Stores new value into key field in the given table. If value for key is not given then it generates new random one just like store_row does.

$self->_driver->update_key($table,$unique_id,$key_name,$key_value);
update_row ($$$$)

Updates multiple fields in the row by unique id and table.

Example:

$self->_driver->update_row($table,$unique_id,\%row);

AUTHORS

Xao, Inc. (c) 2001. This module was developed by Andrew Maltsev <am@xao.com> with help and valuable comments from other team members.

SEE ALSO

Further reading: XAO::FS, XAO::DO::FS::Glue.