Document RDB$GET_TRANSACTION_CN

src/docs/asciidoc/en/refdocs/fblangref40/_fblangref40-functions-scalar.adoc

@@ -3691,3 +3691,61 @@ A plain `AVG(Weight)` would include the -1 weights, thus skewing the result.
 
 .See also
 <<fblangref40-scalarfuncs-coalesce>>, <<fblangref40-scalarfuncs-decode>>, <<fblangref40-scalarfuncs-iif>>, <<fblangref40-commons-conditional-case,`CASE`>>
+
+[[fblangref40-scalarfuncs-other]]
+== Other Functions
+
+Functions that don't really fit in any other category.
+
+[[fblangref40-scalarfuncs-gettransactioncn]]
+=== `RDB$GET_TRANSACTION_CN`
+
+.Available in
+DSQL, PSQL
+
+.Result type
+`BIGINT`
+
+.Syntax
+[listing,subs=+quotes]
+----
+RDB$GET_TRANSACTION_CN(_transaction_id_)
+----
+
+[[fblangref40-funcs-tbl-gettransactioncn]]
+.`RDB$GET_TRANSACTION_CN` Function Parameters
+[cols="<1,<3", options="header",stripes="none"]
+|===
+^| Parameter
+^| Description
+
+|transaction_id
+|Transaction id
+|===
+
+`RDB$GET_TRANSACTION_CN` returns the commit number ("`CN`") of the supplied transaction.
+
+If the return value is greater than 1, it is the actual _CN_ of the transaction if it was committed after the database was started.
+
+The function can also return one of the following results, indicating the commit status of the transaction:
+
+[horizontal]
+`-2`:: Transaction is dead (rolled back)
+`-1`:: Transaction is in limbo
+`{nbsp}0`:: Transaction is still active
+`{nbsp}1`:: Transaction committed before the database started or less than the Oldest Interesting Transaction for the database
+`NULL`:: Transaction number supplied is NULL or greater than Next Transaction for the database
+
+[NOTE]
+====
+For more information about _CN_, consult the _Firebird 4.0 Release Notes_.
+====
+
+[[fblangref40-scalarfuncs-gettransactioncn-exmpl]]
+==== `RDB$GET_TRANSACTION_CN` Examples
+
+[source]
+----
+select rdb$get_transaction_cn(current_transaction) from rdb$database;
+select rdb$get_transaction_cn(123) from rdb$database;
+----