Oracle ALL

Summary: in this tutorial, you will learn how to use the Oracle ALL operator to compare a value with a list or subquery.

Introduction to the Oracle ALL operator

The Oracle ALL operator is used to compare a value to a list of values or result set returned by a subquery.

The following shows the syntax of the ALL operator used with a list or a subquery:

operator ALL ( v1, v2, v3)

operator ALL ( subquery) 

In this syntax:

• The ALL operator must be preceded by an comparison operator such as =, != >,>=, <, <= and followed by a list or subquery.
• The list or subquery must be surrounded by the parentheses.

When you use the ALL operator to compare a value to a list, Oracle expands the initial condition to all elements of the list and uses the AND operator to combine them as shown below:

SELECT
    *
FROM
    table_name
WHERE
    c > ALL (
        v1,
        v2,
        v3
    );

--  transform the ALL operator

SELECT
    *
FROM
    table_name
WHERE
    c > v1
    AND c > v2
    AND c > v3;

If you use the ALL operator to compare a value with a result set returned by a subquery, Oracle performs a two-step transformation as shown below:

SELECT product_name,
       list_price
FROM products
WHERE list_price > ALL
    ( SELECT list_price
     FROM products
     WHERE category_id = 1 )
ORDER BY product_name;

-- 1st step: transformation that uses ANY

SELECT product_name,
       list_price
FROM products p1
WHERE NOT( p1.list_price <= ANY
            (SELECT list_price
             FROM products p2
             WHERE category_id = 1 ))
ORDER BY product_name; 

-- 2nd step: transformation that eliminates ANY
SELECT product_name,
       list_price
FROM products p1
WHERE NOT EXISTS
    (SELECT p2.list_price
     FROM products p2
     WHERE p2.category_id = 1
       AND p2.list_price >= p1.list_price )
ORDER BY product_name;

If the subquery returns no rows, then the following condition evaluates to true:

 operator ALL (subquery)

Which means that the query that uses the above condition in the WHERE clause will return all rows in case the subquery return no rows.

SELECT
    *
FROM
    table_name
WHERE
    col operator ALL(subquery);

Oracle ALL operator examples

The following example finds the average list price of products in each product category:

SELECT
    ROUND( AVG( list_price ),2 ) avg_list_price
FROM
    products
GROUP BY
    category_id
ORDER BY
    avg_list_price DESC;

1) col > ALL (list)

The expression evaluates to true if the col is greater than the biggest value in the list.

For example, the following query finds all products whose list prices are greater than the highest price of the average price list:

SELECT
    product_name,
    list_price
FROM
    products
WHERE
    list_price > ALL(
        SELECT
            AVG( list_price )
        FROM
            products
        GROUP BY
            category_id
    )
ORDER BY
    list_price ASC;

2) col < ALL(list)

The expression evaluates to true if the col is smaller than the smallest value in the list.

For example, the following query finds all products whose list prices are less than the lowest price in the average price list:

SELECT
    product_name,
    list_price
FROM
    products
WHERE
    list_price < ALL(
        SELECT
            AVG( list_price )
        FROM
            products
        GROUP BY
            category_id
    )
ORDER BY
    list_price DESC;

3) col >= ALL(list)

The expression evaluates to true if the col is greater than or equal to the biggest value in the list.

The following statement returns CPU products whose list price is greater than or equal to 2200:

SELECT
    product_name,
    list_price
FROM
    products
WHERE
    list_price >= ALL(
        1000,
        1500,
        2200
    )
    AND category_id = 1
ORDER BY
    list_price DESC;

3) col <= ALL(list)

The expression evaluates to true if the col is less than or equal to the smallest value in the list.

The following statement returns the CPU products whose list price is less than or equal to 977.99, which is the smallest value in the list.

SELECT
    product_name,
    list_price
FROM
    products
WHERE
    list_price <= ALL(
        977.99,
        1000,
        2200
    )
    AND category_id = 1
ORDER BY
    list_price DESC;

5) col = ALL ( list)

The expression evaluates to true if the col matches all values in the list.

6) col != ALL (list)

The expression evaluates to true if the col does not match any values in the list.

In this tutorial, you have learned how to use the Oracle ALL operator to compare a value with a list or subquery.