IS_ASCII
IS_ASCII is used to test if a string contains only ASCII characters.
Syntax
IS_ASCII( expr ) --> BOOL
Arguments
| Parameter | Description | 
|---|---|
| 
 | A general value expression or a literal to test. | 
Returns
Returns TRUE when expr contains only ASCII characters (0-127) or FALSE otherwise.
Notes
- If the expression to test is - NULL,- IS_ASCIIreturns- NULL.
Examples
For these examples, consider the following table and contents:
CREATE TABLE dictionary (id INT NOT NULL, text TEXT);
INSERT INTO dictionary VALUES (1, '行こう'), (2, '乾杯'), (3, 'L''chaim');
SELECT id, text, IS_ASCII(text) FROM dictionary;
IS NULL
id | text     | is_ascii
---+----------+----------
 1 | 行こう     | false
 2 | 乾杯     | false
 3 | L'chaim  | true