For the WHERE clause

comparison-predicate::=value-expression comparison-operator value-expression
    comparison-operator::={<|<=|>|>=|=|!=}

For the HAVING clause

comparison-predicate::=comparison-operand comparison-operator comparison-operand
    comparison-operand::={column-specification|column-name|aggregate-function|constant}
    comparison-operator::={<|<=|>|>=|=|!=}

Specifies the condition for determining a true or false logical value.

value-expression

For details about specifying a value expression, see 4.4.19 Value expression.

comparison-operator

Specify <, <=, >, >=, =, or != as the comparison operator.

comparison-operand

Specify a column specification, an aggregate function, or a constant as the targets of the comparison.

If the preceding FROM clause only references a single relation, you can specify just a column name for that comparison operand.

column-specification

For details about column specification, see 3.2.4 Specifying names.

column-name

If the succeeding FROM clause only references a single relation, you can specify just a column name.

If the succeeding FROM clause references multiple relations, you must use a column specification.

aggregate-function

For details about aggregate functions, see 4.4.12 Aggregate functions.

constant

For details about constants, see 4.4.20 Constant.

The following table shows the meanings of comparison operators, using comparison operand X, the comparison operator, and comparison operand Y as comparison predicates.

Table 4-7 Comparison operator types and functions

No.	Comparison operator specification	Meaning
1	comparison-operand X=comparison-operand Y	True if comparison operand X is equal to comparison operand Y.
2	comparison-operand X!=comparison-operand Y	True if comparison operand X is not equal to comparison operand Y.
3	comparison-operand X<comparison-operand Y	True if comparison operand X is less than comparison operand Y.
4	comparison-operand X<=comparison-operand Y	True if comparison operand X is less than or equal to comparison operand Y.
5	comparison-operand X>comparison-operand Y	True if comparison operand X is greater than comparison operand Y.
6	comparison-operand X>=comparison-operand Y	True if comparison operand X is greater than or equal to comparison operand Y.

• For the left and right comparison operands, only specify data types that can be compared. For details about data types that can be compared, see 3.4 Data comparison.
• If the data types being compared differ in how numeric data is compared, the data type with the wider range of values is used for comparison. The range hierarchy is as follows:
  

  DECIMAL = NUMERIC > FLOAT = DOUBLE > REAL > BIGINT > INTEGER > SMALLINT > TINYINT

• A constant cannot be compared with another constant. If an attempt is made to do this, an error occurs.
• A column specification or a column name must be included in either a comparison operand or a value expression.
• In a value expression specified for a comparison predicate, the four arithmetic operations cannot be executed on different data identifiers. For example, the following specification is invalid:
  

  WHERE s1.a + s2.a < 5

Outputs data in which the value of column a in relation s1 is less than 5. The underlined part indicates a comparison predicate.

REGISTER QUERY q1 SELECT * FROM s1[RANGE 10 SECOND] WHERE s1.a < 5;