1DBSchema::Column(3) User Contributed Perl Documentation DBSchema::Column(3)
2
6 DBIx::DBSchema::Column - Column objects
7
9 use DBIx::DBSchema::Column;
10 #named params with a hashref (preferred)
12 $column = new DBIx::DBSchema::Column ( {
13 'name' => 'column_name',
14 'type' => 'varchar'
15 'null' => 'NOT NULL',
16 'length' => 64,
17 'default' => '',
18 'local' => '',
19 } );
20 #list
22 $column = new DBIx::DBSchema::Column ( $name, $sql_type, $nullability, $length, $default, $local );
23 $name = $column->name;
25 $column->name( 'name' );
26 $sql_type = $column->type;
28 $column->type( 'sql_type' );
29 $null = $column->null;
31 $column->null( 'NULL' );
32 $column->null( 'NOT NULL' );
33 $column->null( '' );
34 $length = $column->length;
36 $column->length( '10' );
37 $column->length( '8,2' );
38 $default = $column->default;
40 $column->default( 'Roo' );
41 $sql_line = $column->line;
43 $sql_line = $column->line($datasrc);
44 $sql_add_column = $column->sql_add_column;
46 $sql_add_column = $column->sql_add_column($datasrc);
47
49 DBIx::DBSchema::Column objects represent columns in tables (see
50 DBIx::DBSchema::Table).
51
53 new HASHREF
54 new [ name [ , type [ , null [ , length [ , default [ , local ] ] ] ]
55 ] ]
56 Creates a new DBIx::DBSchema::Column object. Takes a hashref of
57 named parameters, or a list. name is the name of the column. type
58 is the SQL data type. null is the nullability of the column
59 (intrepreted using Perl's rules for truth, with one exception: `NOT
60 NULL' is false). length is the SQL length of the column. default
61 is the default value of the column. local is reserved for data‐
62 base-specific information.
63 Note: If you pass a scalar reference as the default rather than a
65 scalar value, it will be dereferenced and quoting will be forced
66 off. This can be used to pass SQL functions such as "$now()" or
67 explicit empty strings as '' as defaults.
68 name [ NAME ]
70 Returns or sets the column name.
71 type [ TYPE ]
73 Returns or sets the column type.
74 null [ NULL ]
76 Returns or sets the column null flag (the empty string is equiva‐
77 lent to `NOT NULL')
78 length [ LENGTH ]
80 Returns or sets the column length.
81 default [ LOCAL ]
83 Returns or sets the default value.
84 local [ LOCAL ]
86 Returns or sets the database-specific field.
87 table_obj [ TABLE_OBJ ]
89 Returns or sets the table object (see DBIx::DBSchema::Table). Typ‐
90 ically set internally when a column object is added to a table
91 object.
92 table_name
94 Returns the table name, or the empty string if this column has not
95 yet been assigned to a table.
96 line [ DATABASE_HANDLE ⎪ DATA_SOURCE [ USERNAME PASSWORD [ ATTR ] ] ]
98 Returns an SQL column definition.
99 The data source can be specified by passing an open DBI database
101 handle, or by passing the DBI data source name, username and pass‐
102 word.
103 Although the username and password are optional, it is best to call
105 this method with a database handle or data source including a valid
106 username and password - a DBI connection will be opened and the
107 quoting and type mapping will be more reliable.
108 If passed a DBI data source (or handle) such as `DBI:mysql:data‐
110 base' or `DBI:Pg:dbname=database', will use syntax specific to that
111 database engine. Currently supported databases are MySQL and Post‐
112 greSQL. Non-standard syntax for other engines (if applicable) may
113 also be supported in the future.
114 sql_add_column [ DBH ]
116 Returns a list of SQL statements to add this column to an existing
117 table. (To create a new table, see "sql_create_table" in
118 DBIx::DBSchema::Table instead.)
119 The data source can be specified by passing an open DBI database
121 handle, or by passing the DBI data source name, username and pass‐
122 word.
123 Although the username and password are optional, it is best to call
125 this method with a database handle or data source including a valid
126 username and password - a DBI connection will be opened and the
127 quoting and type mapping will be more reliable.
128 If passed a DBI data source (or handle) such as
130 `DBI:Pg:dbname=database', will use PostgreSQL-specific syntax.
131 Non-standard syntax for other engines (if applicable) may also be
132 supported in the future.
133 sql_alter_column PROTOTYPE_COLUMN [ DATABASE_HANDLE ⎪ DATA_SOURCE [
135 USERNAME PASSWORD [ ATTR ] ] ]
136 Returns a list of SQL statements to alter this column so that it is
137 identical to the provided prototype column, also a
138 DBIx::DBSchema::Column object.
139 #Optionally, the data source can be specified by passing an open DBI database
141 #handle, or by passing the DBI data source name, username and password.
142 #
143 #If passed a DBI data source (or handle) such as `DBI:Pg:dbname=database', will
144 #use PostgreSQL-specific syntax. Non-standard syntax for other engines (if
145 #applicable) may also be supported in the future.
146 #
147 #If not passed a data source (or handle), or if there is no driver for the
148 #specified database, will attempt to use generic SQL syntax.
149 Or should, someday. Right now it knows how to change NOT NULL into
151 NULL and vice-versa.
152
154 Ivan Kohler <ivan-dbix-dbschema@420.am>
155
157 Copyright (c) 2000-2006 Ivan Kohler Copyright (c) 2007 Freeside Inter‐
158 net Services, Inc. All rights reserved. This program is free soft‐
159 ware; you can redistribute it and/or modify it under the same terms as
160 Perl itself.
161
163 The new() method should warn that "Old-style $class creation without
164 named parameters is deprecated!"
165 Better documentation is needed for sql_add_column
167 line() and sql_add_column() hav database-specific foo that should be
169 abstracted into the DBIx::DBSchema:DBD:: modules.
170
172 DBIx::DBSchema::Table, DBIx::DBSchema, DBIx::DBSchema::DBD, DBI
173perl v5.8.8 2002-11-29 DBSchema::Column(3)