Counts how many characters a string has.
LENGTH(<text>)
CHAR_LENGTH(<text>)
Returns the number of characters, spaces included. CHAR_LENGTH does the same and is part of the SQL standard. Often used to check length: a password that's too short, a name that's too long.
employees
| name | department | salary | bonus | phone |
|---|---|---|---|---|
| Emma | backend | 1200 | 300 | +44 7700 900123 |
| Liam | backend | 1000 | NULL | NULL |
| Olivia | frontend | 1350 | 150 | +44 7700 900456 |
| Noah | frontend | 950 | NULL | +44 7700 900789 |
| Sophia | design | 1200 | 200 | NULL |
These tables already exist in the sandbox — the examples below use them. Want to try this in your own database? Copy the SQL.
| letters | with_space |
|---|---|
| 10 | 9 |
| name | name_length |
|---|---|
| Emma | 4 |
| Liam | 4 |
| Olivia | 6 |
| Noah | 4 |
| Sophia | 6 |
| name |
|---|
| Olivia |
| Sophia |
It counts characters, not bytes: LENGTH('café') gives 4, even though it takes 5 bytes in memory. Bytes are counted by OCTET_LENGTH.
For NULL the result is NULL too, not 0. Only an empty string '' gives zero.
With the char(n) type, trailing spaces aren't counted: LENGTH('ab '::char(4)) gives 2, while for text it's 4.