4.4.5 FROM clause

Organization of this subsection
(1) Format
(2) Function
(3) Operands
(4) Syntax rules
(5) Notes
(6) Usage example

(1) Format

FROM-clause::=FROM[Figure]relation-reference[,relation-reference]...

(2) Function

Specifies one or more relations (relation references). The relation that is retrieved by the FROM clause becomes the target of the WHERE or HAVING clauses.

If no WHERE or HAVING clauses are specified, the relation acquired by the FROM clause becomes the target of the SELECT clause.

If multiple relations are specified, the relation returned by the FROM clause is formed by connecting the rows from each relation in the order in which they are defined. The total number of rows is the product of the number of rows in the individual relations.

(3) Operands

relation-reference

For details about specifying a relation reference, see 4.4.14 Relation reference.

The number of relation references that can be specified is in the range from 1 to 64.

(4) Syntax rules

None.

(5) Notes

The relation returned by the FROM clause is a single group without grouped columns.

(6) Usage example

Specifies relation s1 is to be returned. The underlined part indicates the FROM clause.

REGISTER QUERY q1 SELECT * FROM s1[ROWS 100];