Comparison operators compare one expression to another. The result of such a comparison can be TRUE, FALSE, or UNKNOWN (if one of the operands is NULL). The Salesforce driver considers the UNKNOWN result as FALSE. The following table lists the supported comparison operators.

Table 1. Comparison Operators
Operator Purpose Example
= Equality test. 
SELECT * FROM emp WHERE sal = 1500
!= <> Inequality test. 
SELECT * FROM emp WHERE sal != 1500
> < “Greater than" and "less than" tests. 
SELECT * FROM emp WHERE sal > 1500
SELECT * FROM emp WHERE sal < 1500
>= <= “Greater than or equal to" and "less than or equal to" tests. 
SELECT * FROM emp WHERE sal >= 1500
SELECT * FROM emp WHERE sal <= 1500
[NOT] IN “Equal to any member of" test. 
SELECT * FROM emp WHERE job IN 
('CLERK','ANALYST')
SELECT * FROM emp WHERE sal IN 
(SELECT sal FROM emp WHERE deptno = 30)
[NOT] BETWEEN x AND y "Greater than or equal to x" and "less than or equal to y." 
SELECT * FROM emp WHERE sal BETWEEN 
2000 AND 3000
EXISTS Tests for existence of rows in a subquery. 
SELECT empno, ename, deptno FROM 
emp e
WHERE EXISTS (SELECT deptno FROM
dept WHERE e.deptno = dept.deptno)
IS [NOT] NULL Tests whether the value of the column or expression is NULL. 
SELECT * FROM emp WHERE ename 
IS 
NOT NULL 
SELECT * FROM emp WHERE ename IS 
NULL
ESCAPE clause in LIKE operatorLIKE ’pattern string’ ESCAPE ’c’ The Escape clause is supported in the LIKE predicate to indicate the escape character. Escape characters are used in the pattern string to indicate that any wildcard character that is after the escape character in the pattern string should be treated as a regular character.

The default escape character is backslash (\).

 
SELECT * FROM emp WHERE ENAME LIKE
'J%\_%' ESCAPE '\'
This matches all records with names that start with letter 'J' and have the '_' character in them.
SELECT * FROM emp WHERE ENAME LIKE
'JOE\_JOHN' ESCAPE '\'
This matches only records with name ’JOE_JOHN’.