Removes spaces (or other characters) at the start and end of a string.
TRIM(<text>)
TRIM(LEADING <characters> FROM <text>)
TRIM(TRAILING <characters> FROM <text>)
TRIM(BOTH <characters> FROM <text>)
Without extra words it removes spaces from both ends. LEADING — only at the start, TRAILING — only at the end, BOTH — from both sides. Most often it's used to clean up what people typed: ' Emma ' from a form is no longer 'Emma' when you compare.
| trimmed | length_before | length_after |
|---|---|---|
| Emma | 10 | 4 |
Spaces aren't visible in the result table, so their lengths are shown next to it: there were 10 characters, 4 are left.
| no_zeros | no_dots |
|---|---|
| 123 | Hello |
The second argument is a set of characters, not a word: TRIM(BOTH 'ab' FROM 'abba_x_ba') strips every a and b from the edges and gives _x_.
Without arguments it removes only ordinary spaces — tabs and line breaks stay. For those, list the characters explicitly: TRIM(E' \t\n' FROM <text>).
TRIM doesn't touch spaces inside the string: 'Emma Wilson' keeps its three spaces.