Oracle PIVOT operator

Oracle PIVOT operator allows you to cross-request a table to those who started using Oracle 11g. This means that you can combine your results and rotate rows into columns.

Syntax for the PIVOT operator in Oracle/PLSQL

SELECT * FROM
(
SELECT column1_id, column2_id
FROM tabs
WHERE conds
)
PIVOT
(
aggregate_function(column2_id)
FOR column2_id
IN ( expr1_id, expr2_id, ... expr_n_id) | subquery
)
ORDER BY expression_id [ ASC | DESC ];

Parameters or arguments

• aggregate_function – It can be a function such as SUM, COUNT, MIN, MAX or AVG.
• IN (expr1_id, expr2_id, … expr_n_id) – List of values to rotate column2_id in the header of the cross tabular query result.
• subquery – A subquery can be used instead of a list of values. In this case, the results of the subquery will be used to determine the values for rotating column2 in the header of the cross tabular query result.

The PIVOT operator can be used in future versions of Oracle/PLSQL

Oracle 12c, Oracle 11g

How to use the PIVOT offer in Oracle

We’ll base our example on a table called orders with the following definition:

CREATE TABLE ords
( order_id integer NOT NULL,
custom_ref varchar2(50) NOT NULL,
order_date date,
prod_id integer,
quantity_id integer,
CONSTRAINT orders_pk_id PRIMARY KEY (order_id)
);

In order to show you the data for this example, we will select records from the order table with the following SELECT query:

SELECT order_id, custom_ref, prod_id
FROM ords
ORDER BY ord_id;

These are the ords table entries. We will use these records to demonstrate how the PIVOT operator works:

Now, create a cross tabular query using the following PIVOT operator:

SELECT * FROM
(
SELECT custom_ref, prod_id
FROM ords
)
PIVOT
(
COUNT(prod_id)
FOR prod_id IN (10, 20, 30)
)
ORDER BY custom_ref;

In this example, the PIVOT operator will return the following results:

Now let’s take apart the PIVOT operator and explain how it works.

Field specifics for inclusion

First, we want to specify which fields to include in the cross table. In this example, we want to include the customer_ref and product_id fields. This is done using the next part of the query:

(
SELECT custom_ref, prod_id
FROM ords
)

You can list the columns to be included in any order.

Specifics of the aggregate function

Further, when creating our cross table query, we need to specify the aggregate function. You can use any of the functions such as SUM, COUNT, MIN, MAX or AVG.

In this example, we will use the COUNT function. This will allow us to calculate the number of product_id values that meet our criteria. This is done using the next part of the query:

PIVOT
(
COUNT(prod_id)

Specificity of PIVOT values

Finally, we must specify PIVOT values to be included in the result. They will be used as column headers in our cross tabular query. To specify PIVOT values, you can use either the list of values in brackets or the subquery.

In this example we will only return the following product_id values: 10, 20, 30. In our cross tabular query, these values will become our column headers. In addition, note that these values are the final list of product_id values and will not necessarily contain all possible values.

This is done using the next part of the query:

FOR prod_id IN (10, 20, 30)
)

Now that we have it all together, we get the next PIVOT table:

Oracle Pivot clause