RDB$GET_CONTEXT()
Retrieves the value of a context variable from a namespace
VARCHAR(255)
RDB$GET_CONTEXT ('<namespace>', <varname>) <namespace> ::= SYSTEM | USER_SESSION | USER_TRANSACTION | DDL_TRIGGER <varname> ::= A case-sensitive quoted string of max. 80 characters
Parameter | Description |
---|---|
namespace |
Namespace |
varname |
Variable name;case-sensitive with a maximum length of 80 characters |
The USER_SESSION
and USER_TRANSACTION
namespaces are initially empty.A user can create and set variables with RDB$SET_CONTEXT()
and retrieve them with RDB$GET_CONTEXT()
.The SYSTEM
namespace is read-only.The DDL_TRIGGER
namespace is only valid in DDL triggers, and is read-only.The SYSTEM
and DDL_TRIGGER
namespaces contain a number of predefined variables, shown below.
If the polled variable exists in the given namespace, its value will be returned as a string of max. 255 characters.If the namespace doesn’t exist or if you try to access a non-existing variable in the SYSTEM
or DDL_TRIGGER
namespace, an error is raised.If you request a non-existing variable in one of the user namespaces, NULL
is returned.Both namespace and variable names must be given as single-quoted, case-sensitive, non-NULL
strings.