1DBSchema(3) User Contributed Perl Documentation DBSchema(3)
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6 DBIx::DBSchema - Database-independent schema objects
7
9 use DBIx::DBSchema;
10 $schema = new DBIx::DBSchema @dbix_dbschema_table_objects;
12 $schema = new_odbc DBIx::DBSchema $dbh;
13 $schema = new_odbc DBIx::DBSchema $dsn, $user, $pass;
14 $schema = new_native DBIx::DBSchema $dbh;
15 $schema = new_native DBIx::DBSchema $dsn, $user, $pass;
16 $schema->save("filename");
18 $schema = load DBIx::DBSchema "filename" or die $DBIx::DBSchema::errstr;
19 $schema->addtable($dbix_dbschema_table_object);
21 @table_names = $schema->tables;
23 $DBIx_DBSchema_table_object = $schema->table("table_name");
25 @sql = $schema->sql($dbh);
27 @sql = $schema->sql($dsn, $username, $password);
28 @sql = $schema->sql($dsn); #doesn't connect to database - less reliable
29 $perl_code = $schema->pretty_print;
31 %hash = eval $perl_code;
32 use DBI qw(:sql_types); $schema = pretty_read DBIx::DBSchema \%hash;
33
35 DBIx::DBSchema objects are collections of DBIx::DBSchema::Table objects
36 and represent a database schema.
37 This module implements an OO-interface to database schemas. Using this
39 module, you can create a database schema with an OO Perl interface.
40 You can read the schema from an existing database. You can save the
41 schema to disk and restore it in a different process. You can write
42 SQL CREATE statements statements for different databases from a single
43 source. In recent versions, you can transform one schema to another,
44 adding any necessary new columns and tables (and, as of 0.33, indices).
45 Currently supported databases are MySQL, PostgreSQL and SQLite. Sybase
47 and Oracle drivers are partially implemented. DBIx::DBSchema will
48 attempt to use generic SQL syntax for other databases. Assistance
49 adding support for other databases is welcomed. See
50 DBIx::DBSchema::DBD, "Driver Writer's Guide and Base Class".
51
53 new TABLE_OBJECT, TABLE_OBJECT, ...
54 Creates a new DBIx::DBSchema object.
55 new_odbc DATABASE_HANDLE | DATA_SOURCE USERNAME PASSWORD [ ATTR ]
57 Creates a new DBIx::DBSchema object from an existing data source,
58 which can be specified by passing an open DBI database handle, or
59 by passing the DBI data source name, username, and password. This
60 uses the experimental DBI type_info method to create a schema with
61 standard (ODBC) SQL column types that most closely correspond to
62 any non-portable column types. Use this to import a schema that
63 you wish to use with many different database engines. Although
64 primary key and (unique) index information will only be read from
65 databases with DBIx::DBSchema::DBD drivers (currently MySQL and
66 PostgreSQL), import of column names and attributes *should* work
67 for any database. Note that this method only uses "ODBC" column
68 types; it does not require or use an ODBC driver.
69 new_native DATABASE_HANDLE | DATA_SOURCE USERNAME PASSWORD [ ATTR ]
71 Creates a new DBIx::DBSchema object from an existing data source,
72 which can be specified by passing an open DBI database handle, or
73 by passing the DBI data source name, username and password. This
74 uses database-native methods to read the schema, and will preserve
75 any non-portable column types. The method is only available if
76 there is a DBIx::DBSchema::DBD for the corresponding database
77 engine (currently, MySQL and PostgreSQL).
78 load FILENAME
80 Loads a DBIx::DBSchema object from a file. If there is an error,
81 returns false and puts an error message in $DBIx::DBSchema::errstr;
82 save FILENAME
84 Saves a DBIx::DBSchema object to a file.
85 addtable TABLE_OBJECT
87 Adds the given DBIx::DBSchema::Table object to this DBIx::DBSchema.
88 tables
90 Returns a list of the names of all tables.
91 table TABLENAME
93 Returns the specified DBIx::DBSchema::Table object.
94 sql [ DATABASE_HANDLE | DATA_SOURCE [ USERNAME PASSWORD [ ATTR ] ] ]
96 Returns a list of SQL `CREATE' statements for this schema.
97 The data source can be specified by passing an open DBI database
99 handle, or by passing the DBI data source name, username and
100 password.
101 Although the username and password are optional, it is best to call
103 this method with a database handle or data source including a valid
104 username and password - a DBI connection will be opened and used to
105 check the database version as well as for more reliable quoting and
106 type mapping. Note that the database connection will be used
107 passively, not to actually run the CREATE statements.
108 If passed a DBI data source (or handle) such as
110 `DBI:mysql:database' or `DBI:Pg:dbname=database', will use syntax
111 specific to that database engine. Currently supported databases
112 are MySQL and PostgreSQL.
113 If not passed a data source (or handle), or if there is no driver
115 for the specified database, will attempt to use generic SQL syntax.
116 sql_update_schema [ OPTIONS_HASHREF, ] PROTOTYPE_SCHEMA [
118 DATABASE_HANDLE | DATA_SOURCE [ USERNAME PASSWORD [ ATTR ] ] ]
119 Returns a list of SQL statements to update this schema so that it
120 is idential to the provided prototype schema, also a DBIx::DBSchema
121 object.
122 Right now this method knows how to add new tables and alter
124 existing tables, including indices. If specifically requested by
125 passing an options hashref with drop_tables set true before all
126 other arguments, it will also drop tables.
127 See "sql_alter_table" in DBIx::DBSchema::Table, "sql_add_coumn" in
129 DBIx::DBSchema::Column and "sql_alter_column" in
130 DBIx::DBSchema::Column for additional specifics and limitations.
131 The data source can be specified by passing an open DBI database
133 handle, or by passing the DBI data source name, username and
134 password.
135 Although the username and password are optional, it is best to call
137 this method with a database handle or data source including a valid
138 username and password - a DBI connection will be opened and used to
139 check the database version as well as for more reliable quoting and
140 type mapping. Note that the database connection will be used
141 passively, not to actually run the CREATE statements.
142 If passed a DBI data source (or handle) such as
144 `DBI:mysql:database' or `DBI:Pg:dbname=database', will use syntax
145 specific to that database engine. Currently supported databases
146 are MySQL and PostgreSQL.
147 If not passed a data source (or handle), or if there is no driver
149 for the specified database, will attempt to use generic SQL syntax.
150 update_schema [ OPTIONS_HASHREF, ] PROTOTYPE_SCHEMA, DATABASE_HANDLE |
152 DATA_SOURCE [ USERNAME PASSWORD [ ATTR ] ]
153 Same as sql_update_schema, except actually runs the SQL commands to
154 update the schema. Throws a fatal error if any statement fails.
155 pretty_print
157 Returns the data in this schema as Perl source, suitable for
158 assigning to a hash.
159 pretty_read HASHREF
161 This method is not recommended. If you need to load and save your
162 schema to a file, see the /load and /save methods.
163 Creates a schema as specified by a data structure such as that
165 created by pretty_print method.
166
168 Ivan Kohler <ivan-dbix-dbschema@420.am>
169 Charles Shapiro <charles.shapiro@numethods.com> and Mitchell Friedman
171 <mitchell.friedman@numethods.com> contributed the start of a Sybase
172 driver.
173 Daniel Hanks <hanksdc@about-inc.com> contributed the Oracle driver.
175 Jesse Vincent contributed the SQLite driver and fixes to quiet down
177 internal usage of the old API.
178 Slaven Rezic <srezic@cpan.org> contributed column and table dropping,
180 Pg bugfixes and more.
181
183 Contributions are welcome! I'm especially keen on any interest in the
184 top items/projects below under BUGS.
185
187 Copyright (c) 2000-2007 Ivan Kohler Copyright (c) 2000 Mail Abuse
188 Prevention System LLC Copyright (c) 2007-2010 Freeside Internet
189 Services, Inc. All rights reserved. This program is free software;
190 you can redistribute it and/or modify it under the same terms as Perl
191 itself.
192
194 Multiple primary keys are not yet supported.
195 Foreign keys and other constraints are not yet supported.
197 sql_update_schema doesn't deal with deleted columns yet.
199 Need to port and test with additional databases
201 Each DBIx::DBSchema object should have a name which corresponds to its
203 name within the SQL database engine (DBI data source).
204 pretty_print is actually pretty ugly.
206 pretty_print isn't so good about quoting values... save/load is a much
208 better alternative to using pretty_print/pretty_read
209 pretty_read is pretty ugly too.
211 pretty_read should *not* create and pass in old-style unique/index
213 indices when nothing is given in the read.
214 Perhaps pretty_read should eval column types so that we can use DBI
216 qw(:sql_types) here instead of externally.
217 Need to support "using" index attribute in pretty_read and in reverse
219 engineering
220 perhaps we should just get rid of pretty_read entirely. pretty_print
222 is useful for debugging, but pretty_read is pretty bunk.
223 sql CREATE TABLE output should convert integers (i.e. use DBI
225 qw(:sql_types);) to local types using DBI->type_info plus a hash to
226 fudge things
227
229 DBIx::DBSchema::Table, DBIx::DBSchema::Index, DBIx::DBSchema::Column,
230 DBIx::DBSchema::DBD, DBIx::DBSchema::DBD::mysql,
231 DBIx::DBSchema::DBD::Pg, FS::Record, DBI
232
234 Hey! The above document had some coding errors, which are explained
235 below:
236 Around line 429:
238 =cut found outside a pod block. Skipping to next block.
239perl v5.12.1 2010-03-27 DBSchema(3)