Appendix C. Metadata overview

Appendix C. Metadata overview
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Appendix C. Metadata overview

Metadata	Level	Type	Description
`db.column`	attribute	string	Table column associated with the attribute. Default value: name of the attribute.
`db.column.sql`	attribute	string	Specifies the column expression used to select value for the attribute. Used in transient classes which represent query results. See the section called “Querying persistent objects”.
`db.index`	attribute	string	If specified, the SQL CREATE script will create index on the attribute. The index will be named as the value of this metadata.
`db.index.unique`	attribute	string	If specified, the SQL CREATE script will create unique index on the attribute. The index will be named as the value of this metadata.
`db.mapping. insertto`	attribute	string	If filtered mapping is used, this metadata specifies the destination table/class for the class attributes.
`db.mapping.type`	type	string	Mapping type for the associated class. Allowed values are: vertical, horizontal, filtered, object. If filtered is used, db.mapping.insertto must be specified. Default value: vertical
`db.oracle. oidSequence.name`	global settings	string	Name of the OID sequence. Default Value: OIDSEQ
`db.oracle. serialIdSequence. name`	global settings	string	Name of the SERIAL ID sequence. Default Value: SERIALSEQ
`db.oracle. type.sql`	type	string	SQL type string used in CREATE TABLE statements as column type. Used by the IopcOracle10g driver. Default values are generated by the driver.
`db.oracle. type.sql.param`	type	string	SQL type string used as parameter type. Used by the IopcOracle10g driver. Default values are generated by the driver.
`db.oracle. workaround.10gOO`	global settings	bool	ADT polymorphic views are generated in a different way to work around a bug in Oracle 10g. See Appendix B, Sample schema SQL scripts.
`db.primarykey`	attribute	bool	Attribute is part of the class/table primary key.
`db.query.skip`	query	N/A	When used as class metadata in a query statement like this: `WHERE x$::Class[db.query.skip]:: attribute$ = 1` the table qualifier is skipped and only the column name is rendered: `WHERE x.attribute = 1`
`db.table`	type	string	Database table associated with the class. Default value: name of the class
`db.transient`	type / attribute	bool	Type level - tells the library that the class is transient and that it does not have an identity. Attribute level - attribute is transient, it is not mapped on any database column. Default value: false
`db.type`	type	string	Database type associated with the class. Default value is tClassName.
`db.type.length`	type / attribute	int	Database column length, maximum number of characters that can be fetched or stored from/to database for the associated type/attribute. Default value: 2000 (for all string types)
`db.type.notNull`	type / attribute	string	Corresponding database table columns will be generated as NOT NULL by the `ScriptsGenerator`.
`db.view.pv`	type	string	Name of the associated polymorphic view. Default value: [db.table]_PV
`db.view.sv`	type	string	Name of the associated simple view. Default value: [db.table]_SV
`db.viewColumn`	attribute	string	View column associated with the attribute. Applies to all views. Default value: [db.column]
`scripts.exclude`	type	bool	No SQL CREATE or DROP scripts are generated for the class.

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Appendix B. Sample schema SQL scripts	Home	Appendix D. DVD content

IOPC2

C++ Object-Relational Mapping Library

Appendix C. Metadata overview