Help Center/ GaussDB/ Developer Guide(Distributed_V2.0-3.x)/ Stored Procedures/ Advanced Packages/ Secondary Encapsulation APIs (Recommended)/ DBE_SESSION
Updated on 2025-08-19 GMT+08:00
View PDF

DBE_SESSION

APIs

Table 1 provides all APIs supported by the DBE_SESSION package. DBE_SESSION takes effect at the session level.

Table 1 DBE_SESSION

API

Description

DBE_SESSION.SET_CONTEXT

Sets the value of an attribute in a specified context.

DBE_SESSION.CLEAR_CONTEXT

Clears the value of an attribute in a specified context.

DBE_SESSION.SEARCH_CONTEXT

Queries the value of an attribute in a specified context.
  • DBE_SESSION.SET_CONTEXT

Sets the value of an attribute in a specified namespace (context). The DBE_SESSION.SET_CONTEXT function prototype is as follows:

1
2
3
4
5
 
DBE_SESSION.SET_CONTEXT(
    namespace text,
    attribute text,
    value text
)returns void;
Table 2 DBE_SESSION.SET_CONTEXT API parameters

Parameter

Type

Input/Output Parameter

Can Be Empty

Description

namespace

TEXT

IN

No

Name of the context to be set. If the context does not exist, create a context. The value contains a maximum of 128 bytes. If the value exceeds 128 bytes, it will be truncated.

attribute

TEXT

IN

No

Attribute name. The value contains a maximum of 1024 bytes. If the value exceeds 1024 bytes, it will be truncated.

value

TEXT

IN

No

Name of the value to be set. The value contains a maximum of 1024 bytes. If the value exceeds 1024 bytes, it will be truncated.
  • DBE_SESSION.CLEAR_CONTEXT

Clears the value of an attribute in a specified namespace (context). The DBE_SESSION.CLEAR_CONTEXT function prototype is as follows:

1
2
3
4
5
 
DBE_SESSION.CLEAR_CONTEXT (
    namespace text,
    client_identifier text default null,
    attribute text default null
)returns void ;
Table 3 DBE_SESSION.CLEAR_CONTEXT API parameters

Parameter

Type

Input/Output Parameter

Can Be Empty

Description

namespace

TEXT

IN

No

Context specified by the user. The value contains a maximum of 128 bytes. If the value exceeds 128 bytes, it will be truncated.

client_identifier

TEXT

IN

Yes

Client authentication. The default value is null. Generally, you do not need to manually set this parameter.

attribute

TEXT

IN

Yes

Attribute to be cleared. The default value is null, indicating that all attributes of the specified context are cleared. The value contains a maximum of 1024 bytes. If the value exceeds 1024 bytes, it will be truncated.

CAUTION:

To ensure forward compatibility, if the parameter value is 'null', all attributes of the specified context are cleared.
  • DBE_SESSION.SEARCH_CONTEXT

Queries the value of an attribute in a specified namespace (context). The DBE_SESSION.SEARCH_CONTEXT function prototype is:

1
2
3
4
 
DBE_SESSION.SEARCH_CONTEXT (
    namespace text,
    attribute text
)returns text;
Table 4 DBE_SESSION.SEARCH_CONTEXT API parameters

Parameter

Type

Input/Output Parameter

Can Be Empty

Description

namespace

TEXT

IN

No

Context specified by the user. The value contains a maximum of 128 bytes. If the value exceeds 128 bytes, it will be truncated.

attribute

TEXT

IN

No

Attribute to be searched for. The value contains a maximum of 1024 bytes. If the value exceeds 1024 bytes, it will be truncated.

Example

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
 
DECLARE
    a text;
BEGIN
    DBE_SESSION.set_context('test', 'gaussdb', 'one');   --Set the gaussdb attribute in the test context to one.
    a := DBE_SESSION.search_context('test', 'gaussdb');
    DBE_OUTPUT.PRINT_LINE(a);
    DBE_SESSION.clear_context('test', 'test','gaussdb');
END;
/
-- The expected result is as follows:
one
ANONYMOUS BLOCK EXECUTE