Update update

Updates columns in a table using select-style dict syntax.

;; Create table
(set t (table [name age] (list (list "Alice" "Bob" "Charlie") [25 30 35])))
┌─────────┬─────┐
│ name    │ age │
├─────────┼─────┤
│ Alice   │ 25  │
│ Bob     │ 30  │
│ Charlie │ 35  │
└─────────┴─────┘

;; Update all rows - multiply age by 2
(set t (update {age: (* age 2) from: t}))
┌─────────┬────────────────────────────┐
│ name    │ age                        │
├─────────┼────────────────────────────┤
│ Alice   │ 50                         │
│ Bob     │ 60                         │
│ Charlie │ 70                         │
├─────────┴────────────────────────────┤
│ 3 rows (3 shown) 2 columns (2 shown) │
└──────────────────────────────────────┘

;; Update with expression referencing column
(set t (table [x y] (list [1 2 3] [10 20 30])))
┌────┬──────────────────────────────────┐
│ x  │ y                                │
├────┼──────────────────────────────────┤
│ 1  │ 10                               │
│ 2  │ 20                               │
│ 3  │ 30                               │
├────┴──────────────────────────────────┤
│ 3 rows (3 shown) 2 columns (2 shown)  │
└───────────────────────────────────────┘
(set t (update {y: (+ y x) from: t}))
┌────┬──────────────────────────────────┐
│ x  │ y                                │
├────┼──────────────────────────────────┤
│ 1  │ 11                               │
│ 2  │ 22                               │
│ 3  │ 33                               │
├────┴──────────────────────────────────┤
│ 3 rows (3 shown) 2 columns (2 shown)  │
└───────────────────────────────────────┘

Returns New Table

update returns a new table - it does NOT modify in place. You must reassign to persist changes:

(set t (update {col: value from: t}))

Syntax

(update {column: expression from: table})

- Uses dictionary syntax like select - from: is required - Column expressions can reference other columns

Where Clause Limitations

The where: clause has limitations with complex expressions. For conditional updates, consider using select to filter rows first, then apply updates to the filtered subset.