比较运算符
编辑比较运算符编辑
用于比较一个或多个表达式的布尔运算符。
相等 (=)编辑
SELECT last_name l FROM "test_emp" WHERE emp_no = 10000 LIMIT 5;
空安全相等 (<=>)编辑
SELECT 'elastic' <=> null AS "equals";
equals
---------------
false
SELECT null <=> null AS "equals";
equals
---------------
true
不相等 (<> 或 !=)编辑
SELECT last_name l FROM "test_emp" WHERE emp_no <> 10000 ORDER BY emp_no LIMIT 5;
比较 (<, <=, >, >=)编辑
SELECT last_name l FROM "test_emp" WHERE emp_no < 10003 ORDER BY emp_no LIMIT 5;
BETWEEN编辑
SELECT last_name l FROM "test_emp" WHERE emp_no BETWEEN 9990 AND 10003 ORDER BY emp_no;
IS NULL/IS NOT NULL编辑
SELECT last_name l FROM "test_emp" WHERE emp_no IS NOT NULL AND gender IS NULL;
IN (<value1>, <value2>, ...)编辑
SELECT last_name l FROM "test_emp" WHERE emp_no IN (10000, 10001, 10002, 999) ORDER BY emp_no LIMIT 5;