[ LATERAL ] <replaceable class="parameter">function_name</replaceable> ( [ <replaceable class="parameter">argument</replaceable> [, ...] ] ) AS ( <replaceable class="parameter">column_definition</replaceable> [, ...] )

[ LATERAL ] ROWS FROM( <replaceable class="parameter">function_name</replaceable> ( [ <replaceable class="parameter">argument</replaceable> [, ...] ] ) [ AS ( <replaceable class="parameter">column_definition</replaceable> [, ...] ) ] [, ...] )

[ WITH ORDINALITY ] [ [ AS ] <replaceable class="parameter">alias</replaceable> [ ( <replaceable class="parameter">column_alias</replaceable> [, ...] ) ] ]

<replaceable class="parameter">from_item</replaceable> [ NATURAL ] <replaceable class="parameter">join_type</replaceable> <replaceable class="parameter">from_item</replaceable> [ ON <replaceable class="parameter">join_condition</replaceable> | USING ( <replaceable class="parameter">join_column</replaceable> [, ...] ) [ AS <replaceable class="parameter">join_using_alias</replaceable> ] ]

<replaceable class="parameter">from_item</replaceable> <replaceable class="parameter">join_type</replaceable> <replaceable class="parameter">from_item</replaceable> { ON <replaceable class="parameter">join_condition</replaceable> | USING ( <replaceable class="parameter">join_column</replaceable> [, ...] ) [ AS <replaceable class="parameter">join_using_alias</replaceable> ] }

<replaceable class="parameter">from_item</replaceable> NATURAL <replaceable class="parameter">join_type</replaceable> <replaceable class="parameter">from_item</replaceable>

<replaceable class="parameter">from_item</replaceable> CROSS JOIN <replaceable class="parameter">from_item</replaceable>

<phrase>and <replaceable class="parameter">grouping_element</replaceable> can be one of:</phrase>

<listitem>

<para><literal>FULL [ OUTER ] JOIN</literal></para>

</listitem>

<listitem>

<para><literal>CROSS JOIN</literal></para>

</listitem>

</itemizedlist>

For the <literal>INNER</literal> and <literal>OUTER</literal> join types, a

join condition must be specified, namely exactly one of

<literal>NATURAL</literal>, <literal>ON <replaceable

class="parameter">join_condition</replaceable></literal>, or

<literal>ON <replaceable

class="parameter">join_condition</replaceable></literal>,

<literal>USING (<replaceable

class="parameter">join_column</replaceable> [, ...])</literal>.

See below for the meaning. For <literal>CROSS JOIN</literal>,

none of these clauses can appear.

class="parameter">join_column</replaceable> [, ...])</literal>,

or <literal>NATURAL</literal>. See below for the meaning.

</para>

<para>

In the absence of parentheses, <literal>JOIN</literal>s nest

left-to-right. In any case <literal>JOIN</literal> binds more

tightly than the commas separating <literal>FROM</literal>-list items.

</para>

<para><literal>CROSS JOIN</literal> and <literal>INNER JOIN</literal>

produce a simple Cartesian product, the same result as you get from

listing the two tables at the top level of <literal>FROM</literal>,

but restricted by the join condition (if any).

<literal>CROSS JOIN</literal> is equivalent to <literal>INNER JOIN ON

(TRUE)</literal>, that is, no rows are removed by qualification.

These join types are just a notational convenience, since they

do nothing you couldn't do with plain <literal>FROM</literal> and

<literal>WHERE</literal>.

All the <literal>JOIN</literal> options are just a notational

convenience, since they do nothing you couldn't do with plain

<literal>FROM</literal> and <literal>WHERE</literal>.

</para>

<para><literal>LEFT OUTER JOIN</literal> returns all rows in the qualified

</listitem>

</varlistentry>

<varlistentry>

<term><literal>CROSS JOIN</literal></term>

<listitem>

<para>

<literal>CROSS JOIN</literal> is equivalent to <literal>INNER JOIN ON

(TRUE)</literal>, that is, no rows are removed by qualification.

They produce a simple Cartesian product, the same result as you get from

listing the two tables at the top level of <literal>FROM</literal>,

but restricted by the join condition (if any).

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><literal>LATERAL</literal></term>

<listitem>

<programlisting>

SELECT f.title, f.did, d.name, f.date_prod, f.kind

FROM distributors d, films f

WHERE f.did = d.did

FROM distributors d JOIN films f USING (did);

title | did | name | date_prod | kind

-------------------+-----+--------------+------------+----------