Inner Join inner-join

Performs an inner join between two tables based on matching key columns.

;; Create sample tables
↪ (set x (table [a b c d] 
    (list (list "aaaaaa" "bbbbbbbbbb" "cc" "dd")
          ['I 'J 'K 'I] 
          [0 1 2 3]
          [0 1 2 3])))

↪ (set y (table [a b c d e] 
    (list (list "aa" "bb" "cc" "dd" "ee")
          ['I 'J 'K 'I 'J]
          [0 1 2 3 4]
          [0 1 2 3 4]
          [0 1 2 3 4])))

;; Inner join on single column
↪ (inner-join [a] x y)
┌──────┬───┬───┬───┬───┐
│ a    │ b │ c │ d │ e │
├──────┼───┼───┼───┼───┤
│ cc   │ K │ 2 │ 2 │ 2 │
│ dd   │ I │ 3 │ 3 │ 3 │
└──────┴───┴───┴───┴───┘

;; Inner join on multiple columns
↪ (inner-join [a b] x y)
┌──────┬───┬───┬───┬───┐
│ a    │ b │ c │ d │ e │
├──────┼───┼───┼───┼───┤
│ cc   │ K │ 2 │ 2 │ 2 │
└──────┴───┴───┴───┴───┘

Syntax

(inner-join columns left-table right-table)

- columns: Vector of column names to join on - left-table: First table to join - right-table: Second table to join

Note

• Only keeps rows where the join columns match
• Rows without matches are excluded
• Column names from both tables are preserved
• Join columns must exist in both tables
• Can join on multiple columns by providing a vector of column names

Tip

Use inner join when you only want rows that have matches in both tables