outerjoin
Outer join between two tables or timetables
Syntax
Description
creates the table or timetable, T
= outerjoin(Tleft
,Tright
)T
, as the outer
join of Tleft
and Tright
using
key variables. All
variables with the same names in both tables are key variables. An outer join
combines table rows where the key variables have matching values, but it also
includes rows where the key variables from one input table have no matches in the
other input table. For example, if Tleft
has variables named
Key1
and Var1
, and
Tright
has variables Key1
and
Var2
, then T=outerjoin(Tleft,Tright)
uses
Key1
as a key variable.
The matching values of the key variables in the left and right tables do not have to be in the same order. Outer joins can perform one-to-many and many-to-one matches between the key variables of the two tables. That is, a value that occurs once in a key variable of the left table can have multiple matches in the right table. Similarly, a value that occurs once in a key variable of the right table can have multiple matches in the left table.
You can perform outer joins only on certain combinations of tables and timetables.
If
Tleft
is a table, thenTright
must be a table.outerjoin
returnsT
as a table.If
Tleft
is a timetable, thenTright
can be either a table or a timetable.outerjoin
returnsT
as a timetable for either combination of inputs.
The vectors of row labels of Tleft
and Tright
can be key
variables. Row labels are the row names of a table, or the row times of a
timetable.
performs the outer-join operation with additional options specified by one or more
T
= outerjoin(Tleft
,Tright
,Name,Value
)Name,Value
pair arguments.
Examples
Input Arguments
Output Arguments
More About
Tips
The vector of row labels from an input table or timetable can be a key, alone or in combination with other key variables. Row labels are the row names of a table or the row times of a timetable. To use this vector as a key, specify it as
'Row'
(for the row names of a table), as the name of a timetable vector of row times, or as the value of
, whereT
.Properties.DimensionNames{1}
is the table or timetable.T
In general,
outerjoin
copies row labels from the input tableTleft
to the output tableT
.If
Tleft
has no row labels, thenT
has no row labels.If
Tleft
has row labels, thenouterjoin
copies row labels fromTleft
to create row labels inT
.If you specify row labels from both
Tleft
andTright
as a key pair, thenouterjoin
merges row labels fromTright
into row labels ofT
where needed.If you specify row labels of
Tleft
as a key, but do not specify row labels ofTright
as the matching key, thenouterjoin
creates default row labels inT
where needed.If both
Tleft
andTright
are tables, but you do not specify either input table’s row names as a key, thenouterjoin
does not create row names inT
.
You cannot perform an outer join using the row labels of
Tleft
as the left key and a variable ofTright
as the right key. To perform the outer join, convert the row labels ofTleft
to a table variable and use the new table variable as a key.
Extended Capabilities
Version History
Introduced in R2013b
See Also
join
| innerjoin
| Join
Tables