The DBMS_EPG
package implements the embedded PL/SQL gateway that enables a web browser to invoke a PL/SQL stored procedure through an HTTP listener.
This chapter contains the following topics:
Overview
Security Model
Exceptions
Configuration Subprograms
Authorization Subprograms
The DBMS_EPG
package is a platform on which PL/SQL users develop and deploy PL/SQL web applications. The embedded PL/SQL gateway is an embedded version of the gateway that runs in the XML database HTTP server in the Oracle database. It provides the core features of mod_plsql
in the database but does not require the Oracle HTTP server powered by Apache.
In order to make a PL/SQL application accessible from a browser via HTTP, a Database Access Descriptor (DAD) must be created and mapped to a virtual path. A DAD is a set of configuration values used for database access and the virtual path mapping makes the application accessible under a virtual path of the XML DB HTTP Server. A DAD is represented as a servlet in XML DB HTTP Server.
The XDBADMIN
role is required to invoke the configuration interface. It may invoked by the database user "XDB
".
The authorization interface can be invoked by any user.
The following table lists the exceptions raised by the DBMS_EPG
package.
The DBMS_EPG
package defines a TABLE
type.
This type is used by the procedures GET_ALL_GLOBAL_ATTRIBUTES
, GET_ALL_DAD_ATTRIBUTES
, GET_ALL_DAD_MAPPINGS
, and GET_DAD_LIST
to return lists of attribute names, attribute values, virtual paths, and database access descriptors (DAD).
TYPE VARCHAR2_TABLE IS TABLE OF VARCHAR2(4000) INDEX BY BINARY_INTEGER;
The DBMS_EPG consists of two interfaces:
The Configuration subprogram group contain the subprogram interfaces to examine and modify the global and database access descriptor (DAD) specific settings of the embedded PL/SQL gateway.
Table 37-2 Configuration Subprogram Group
Subprogram | Description |
---|---|
Creates a new DAD |
|
Deletes a DAD attribute |
|
Deletes a global attribute |
|
Drops a DAD |
|
Retrieves all the attributes of a DAD. |
|
Retrieves all virtual paths to which the specified DAD is mapped. |
|
Retrieves all global attributes and values |
|
Retrieves the value of a DAD attribute |
|
Retrieves a list of all DADs for an Embedded Gateway instance. |
|
Retrieves the value of a global attribute |
|
Maps a DAD to the specified virtual path. |
|
Sets the value for a DAD |
|
Sets the value of a global attribute |
|
Unmaps a DAD from the specified virtual path |
The Authorization subprogram group contains the subprogram interfaces to authorize and deauthorize the use of a database user's privileges by the embedded PL/SQL gateway through a specific database access descriptor (DAD)
Table 37-4 DBMS_ALERT Package Subprograms
Subprogram | Description |
---|---|
authorizes a DAD to invoke procedures and access document tables with a database user's privileges |
|
Creates a new DAD |
|
Deauthorizes a DAD with regard to invoking procedures and accessing document tables with a database user's privileges |
|
Deletes a DAD attribute |
|
Deletes a global attribute |
|
Drops a DAD |
|
Retrieves all the attributes of a DAD. |
|
Retrieves all virtual paths to which the specified DAD is mapped. |
|
Retrieves all global attributes and values |
|
Retrieves the value of a DAD attribute |
|
Retrieves a list of all DADs for an Embedded Gateway instance. |
|
Retrieves the value of a global attribute |
|
Maps a DAD to the specified virtual path. |
|
Sets the value for a DAD |
|
Sets the value of a global attribute |
|
Unmaps a DAD from the specified virtual path |
This procedure authorizes a DAD to invoke procedures and access document tables with a database user's privileges. The invoker can always authorize the use of her/his own privileges.
See Also:
Authorization Subprograms for other subprograms in this groupDBMS_EPG.AUTHORIZE_DAD ( dad_name IN VARCHAR2, path IN VARCHAR2 DEFAULT NULL);
Table 37-5 AUTHORIZE_DAD Procedure Parameters
Parameter | Description |
---|---|
|
The name of the DAD to create |
|
The user whose privileges to deauthorize. If use, the invoker is assumed. |
To authorize the use of another user's privileges, the invoker must have the ALTER
USER
system privilege.
The DAD must exist but its "database-username" DAD attribute does not have to be set to user to authorize.
Multiple users can authorize the same DAD and it is up to the DAD's "database-username" setting to decide which user's privileges to use.
Raises an error if the DAD or user does not exist, or the invoker does not have the needed system privilege.
DBMS_EPG.AUTHORIZE_DAD('HR');
This procedure creates a new DAD.
See Also:
Configuration Subprograms for other subprograms in this groupDBMS_EPG.CREATE_DAD ( dad_name IN VARCHAR2, path IN VARCHAR2 DEFAULT NULL);
Table 37-6 CREATE_DAD Procedure Parameters
Parameter | Description |
---|---|
|
The name of the DAD to create |
|
The virtual path to which to map the DAD |
This procedure deauthorizes a DAD with regard to invoking procedures and accessing document tables with a database user's privileges. The invoker can always deauthorize the use of his own privileges.
See Also:
Authorization Subprograms for other subprograms in this groupDBMS_EPG.DEAUTHORIZE_DAD ( dad_name IN VARCHAR2, path IN VARCHAR2 DEFAULT NULL);
Table 37-7 DEAUTHORIZE_DAD Procedure Parameters
Parameter | Description |
---|---|
|
The name of the DAD for which to deauthorize use |
|
The user whose privileges to deauthorize. If use, the invoker is assumed. |
To deauthorize the use of another user's privileges, the invoker must have the ALTER
USER
system privilege.
Raises an error if the DAD or user does not exist, or the invoker does not have the needed system privilege.
DBMS_EPG.DEAUTHORIZE_DAD('HR');
This procedure deletes a DAD attribute.
See Also:
Configuration Subprograms for other subprograms in this groupDBMS_EPG.DELETE_DAD_ATTRIBUTE ( dad_name IN VARCHAR2, attr_name IN VARCHAR2);
Table 37-8 DELETE_DAD_ATTRIBUTE Procedure Parameters
Parameter | Description |
---|---|
|
The name of the DAD for which to delete a DAD attribute |
|
The name of the DAD attribute to delete |
Raises an error if DAD does not exist
This procedure deletes a global attribute.
See Also:
Configuration Subprograms for other subprograms in this groupDBMS_EPG.DELETE_GLOBAL_ATTRIBUTE ( attr_name IN VARCHAR2);
Table 37-9 DELETE_GLOBAL_ATTRIBUTE Procedure Parameters
Parameter | Description |
---|---|
|
The global attribute to delete |
This procedure drops a DAD. All the virtual-path mappings of the DAD will be dropped also
See Also:
Configuration Subprograms for other subprograms in this groupDBMS_EPG.DROP_DAD ( dadname IN VARCHAR2);
Raises an error if the DAD does not exist.
This procedure retrieves all the attributes of a DAD. The outputs are 2 correlated index-by tables of the name/value pairs.
See Also:
Configuration Subprograms for other subprograms in this groupDBMS_EPG.GET_ALL_DAD_ATTRIBUTES ( dad_name IN VARCHAR2, attr_names OUT NOCOPY VARCHAR2_TABLE, attr_values OUT NOCOPY VARCHAR2_TABLE);
Table 37-11 GET_ALL_DAD_ATTRIBUTES Procedure Parameters
Parameter | Description |
---|---|
|
The name of the DAD |
|
The attribute names |
|
The attribute values |
Raises an error if DAD does not exist.
If the DAD has no attributes set, then attr_names
and attr_values
will be set to empty arrays.
This procedure retrieves all virtual paths to which the specified DAD is mapped.
See Also:
Configuration Subprograms for other subprograms in this groupDBMS_EPG.GET_ALL_DAD_MAPPINGS ( dad_name IN VARCHAR2, paths OUT NOCOPY VARCHAR2_TABLE);
Table 37-12 GET_ALL_DAD_MAPPINGS Procedure Parameters
Parameter | Description |
---|---|
|
The name of the DAD |
|
The virtual paths to which h the DAD is mapped |
Raises an error if DAD does not exist.
If the DAD is not mapped to any virtual path, paths
will be set to empty arrays.
This procedure retrieves all global attributes and values. The outputs are 2 correlated index-by tables of the name/value pairs.
See Also:
Configuration Subprograms for other subprograms in this groupDBMS_EPG.GET_ALL_GLOBAL_ATTRIBUTES ( attr_names OUT NOCOPY VARCHAR2_TABLE, attr_values OUT NOCOPY VARCHAR2_TABLE);
Table 37-13 GET_ALL_GLOBAL_ATTRIBUTES Procedure Parameters
Parameter | Description |
---|---|
|
The global attribute names |
|
The values of the global attributes |
If the gateway instance has no global attributes set, then attr_names
and attr_values
will be set to empty arrays.
This procedure retrieves the value of a DAD attribute.
See Also:
Configuration Subprograms for other subprograms in this groupDBMS_EPG.GET_DAD_ATTRIBUTE ( dad_name IN VARCHAR2, attr_name IN VARCHAR2) RETURN VARCHAR2;
Table 37-14 GET_DAD_ATTRIBUTE Procedure Parameters
Parameter | Description |
---|---|
|
The name of the DAD for which to delete an attribute |
|
The name of the attribute to delete |
Returns the DAD attribute value. Returns NULL
if attribute is unknown or has not been set.
Raises an error if DAD does not exist.
This procedure retrieves a list of all DADs for an Embedded Gateway instance.
See Also:
Configuration Subprograms for other subprograms in this groupDBMS_EPG.GET_DAD_LIST ( dad_names OUT NOCOPY VARCHAR2_TABLE);
If no DADs exist then dad_names
will be set to an empty array.
This function retrieves the value of a global attribute.
See Also:
Configuration Subprograms for other subprograms in this groupDBMS_EPG.GET_GLOBAL_ATTRIBUTE ( attr_name IN VARCHAR2) RETURN VARCHAR2;
Table 37-16 GET_GLOBAL_ATTRIBUTE Procedure Parameters
Parameter | Description |
---|---|
|
The global attribute to retrieve |
Returns the global attribute value. Returns NULL
if attribute has not been set or is not a valid attribute.
This procedure maps a DAD to the specified virtual path. If the virtual path exists already, the old virtual-path mapping will be overridden.
See Also:
Configuration Subprograms for other subprograms in this groupDBMS_EPG.MAP_DAD ( dad_name IN VARCHAR2, path IN VARCHAR2);
Table 37-17 MAP_DAD Procedure Parameters
Parameter | Description |
---|---|
|
The name of the DAD to map |
|
The virtual path to map |
Raises and error if the DAD does not exist.
This procedure sets the value for a DAD.
See Also:
Configuration Subprograms for other subprograms in this groupDBMS_EPG.SET_DAD_ATTRIBUTE ( dad_name IN VARCHAR2, attr_name IN VARCHAR2, attr_value IN VARCHAR2);
Table 37-18 SET_DAD_ATTRIBUTE Procedure Parameters
Parameter | Description |
---|---|
|
The name of the DAD for which to set the attribute |
|
The name of the attribute to set |
|
The attribute value to set |
Table 37-19 Mapping Between mod_plsql and Embedded PL/SQL Gateway DAD Attributes
mod_plsql DAD Attribute | Embedded PL/SQL Gateway DAD Attribute | Allows Multiple Occurr-ences | Legal Values |
---|---|---|---|
|
|
No |
String |
|
|
No |
Enumeration of On, Off |
|
|
No |
Enumeration of Basic, SingleSignOn, GlobalOwa, CustomOwa, PerPackageOwa |
|
|
No |
String |
|
|
Yes |
Unsigned integer |
|
|
Yes |
Unsigned integer |
|
|
Yes |
String |
|
|
No |
Unsigned integer |
|
|
No |
String |
|
|
No |
String |
|
|
No |
String |
|
|
No |
String |
|
|
No |
String |
|
|
No |
Enumeration of ApacheStyle, ModplsqlStyle, DebugStyle |
|
|
Yes |
String |
|
|
No |
Unsigned integer |
|
|
No |
Enumeration of On, Off |
|
i |
No |
Enumeration of InfoDebug |
|
|
No |
Enumeration of On, Off |
|
|
No |
Unsigned integer |
|
|
No |
String |
|
|
No |
String |
|
|
No |
String |
|
|
No |
String |
|
|
No |
String |
|
|
No |
Enumeration of StatelessWithResetPackageState, StatelessWithFastRestPackageState, StatelessWithPreservePackageState |
|
|
No |
Enumeration of Char, Raw |
|
|
No |
String |
Raises an error if DAD does not exist or the attribute is unknown.
If attr_name
attribute has been set before, then the old value will be overwritten with the new attr_value
argument.
The embedded gateway assumes default values when the attributes are not set. The default values of the DAD attributes should be sufficient for most users of the embedded gateway. mod_plsql users should note the following
The PlsqlDatabasePassword
attribute is not needed.
The PlsqlDatabaseConnectString
attribute is not needed because the embedded gateway does not support logon to external databases.
DBMS_EPG.SET_DAD_ATTRIBUTE('HR', 'default-page', 'HRApp.home');
This procedure sets the value of a global attribute.
See Also:
Configuration Subprograms for other subprograms in this groupDBMS_EPG.SET_GLOBAL_ATTRIBUTE ( attr_name IN VARCHAR2, attr_value IN VARCHAR2);
Table 37-20 SET_GLOBAL_ATTRIBUTE Procedure Parameters
Parameter | Description |
---|---|
|
The global attribute to set |
|
The attribute value to set |
Table 37-21 Mapping Between mod_plsql and Embedded PL/SQL Gateway Global Attributes
mod_plsql DAD Attribute | Embedded PL/SQL Gateway DAD Attribute | Allows Multiple Occurr-ences | Legal Values |
---|---|---|---|
|
|
No |
Unsigned integer |
|
|
No |
Unsigned integer |
The attribute name is case sensitive. The value may or may not be case-sensitive depending on the attribute.
If attr_name
attribute has been set before, then the old value will be overwritten with the new attr_value
argument.
Raises an error if the attribute is unknown.
dbms_epg.set_global_attribute('max-parameters', '100');
This procedure unmaps a DAD from the specified virtual path. If path is NULL
, the procedure removes all virtual-path mappings for the DAD but keeps the DAD.
See Also:
Configuration Subprograms for other subprograms in this groupDBMS_EPG.UNMAP_DAD ( dad_name IN VARCHAR2, path IN VARCHAR2 DEFAULT NULL);
Table 37-22 UNMAP_DAD Procedure Parameters
Parameter | Description |
---|---|
|
The name of the DAD to unmap |
|
The virtual path to unmap |
Raises and error if the DAD does not exist.