JoinSide.Left - Enumeration

JoinSide.Left (0) is an enumeration that specifies the left or right table of a join. It is a member of the JoinSide.Type and specifies the left table of a join.

Examples

Suppose you have two tables. You can join these two tables using the Table.Join function. When omitting the joinKind argument, this function by default uses JoinSide.Left with an Inner Join:

Table.Join( 
  Table1,   "CustomerID_T1",
  Table2,   "CustomerID_T2"
)

/* is identical to */

Table.Join( 
  Table1,   "CustomerID_T1",
  Table2,   "CustomerID_T2",
  JoinSide.Left
)

Alternatively, you could swap the Joinside argument to JoinSide.Right as follows:

Table.Join( 
  Table1,   "CustomerID_T1",
  Table2,   "CustomerID_T2",
  JoinSide.Right
)

The result of both joins can be found below. At the top of this image, you find the two base tables (Table1 and Table2) that are joined together. Below those you find the output tables using JoinSide.Left and JoinSide.Right.

JoinSide.Left: This setup performs an inner join by default.
JoinSide.Right: Still researching this, the data suggests it’s doing a Left Outer Join.

JoinSide.Type comparison in Power Query M

To replicate this you can make use of:

let
  Table1 = 
   Table.FromRecords (
    {
      [ CustomerID_T1 = 1, Name = "Bob",   Phone = "123-4567" ],
      [ CustomerID_T1 = 2, Name = "Jim",   Phone = "987-6543" ],
      [ CustomerID_T1 = 3, Name = "Paul",  Phone = "543-7890" ],
      [ CustomerID_T1 = 4, Name = "Ringo", Phone = "232-1550" ]
    }
  ),
  Table2    = 
   Table.FromRecords (
    {
      [ OrderID = 1, CustomerID_T2 = 1, Item = "Fishing rod", Price = 100.0 ],
      [ OrderID = 2, CustomerID_T2 = 1, Item = "1 lb. worms", Price = 5.0   ],
      [ OrderID = 3, CustomerID_T2 = 2, Item = "Fishing net", Price = 25.0  ],
      [ OrderID = 4, CustomerID_T2 = 3, Item = "Fish tazer",  Price = 200.0 ],
      [ OrderID = 5, CustomerID_T2 = 3, Item = "Bandaids",    Price = 2.0   ],
      [ OrderID = 6, CustomerID_T2 = 1, Item = "Tackle box",  Price = 20.0  ],
      [ OrderID = 7, CustomerID_T2 = 5, Item = "Bait",        Price = 3.25  ]
    }
  ),
  LeftSide  = Table.Join ( Table1, "CustomerID_T1", Table2, "CustomerID_T2", JoinSide.Left ),
  RightSide = Table.Join ( Table1, "CustomerID_T1", Table2, "CustomerID_T2", JoinSide.Left )
in
  RightSide

Other related enumerations are:

JoinSide.Right

Applies to

Here’s a list of functions that work with JoinSide.Type:

Examples

Related enumerations

Applies to