What is the usage of and in oracle

In Oracle, and is a logical operator, which means "and". It is used to filter the specified conditions. Only when the conditions before and after and are satisfied, the returned result is true. If one of the If the conditional expression is false, the and operator returns false.

The operating environment of this tutorial: Windows 10 system, Oracle 11g version, Dell G3 computer.

What is the usage of and in oracle

The AND operator is a logical operator that combines Boolean expressions and returns true if both expressions are true. The AND operator returns false if one of the expressions is false.

The syntax of the AND operator is as follows:

expression_1 AND expression_2

The following table illustrates the results when using the AND operator to combine true, false, and NULL values:

Normally, AND is used in the WHERE clause of SELECT, DELETE, and UPDATE statements to form conditions for matching data. Additionally, use the AND operator in the predicate of the JOIN clause to form the join condition.

When using multiple logical operators in a declaration, Oracle always evaluates the AND operator first. However, you can use parentheses to change the order of evaluation.

Oracle AND Operator Example

Take the orders table in the following database as an example:

1. Oracle AND combination Examples of two Boolean expressions

The following example finds those orders with a customer number of 2 that have a status of Pending:

SELECT order_id, customer_id, status, TO_CHAR(order_date,'YYYY-MM-DD') AS order_date
FROM orders
WHERE  status = 'Pending'  AND customer_id = 2
ORDER BY order_date;

In this example, the query returns the order that satisfies the two All order information of expressions, that is:

status = 'Pending' and customer_id = 2

Executing the above code can get the following results:

2. Example of Oracle AND combining two or more Boolean expressions

You can use multiple AND operators to combine Boolean expressions.

For example, the following statement retrieves orders that meet all of the following conditions:

Placed in 2017.

The number of the salesperson in charge is 60.

has shipping status.

Refer to the following query statement:

SELECT
    order_id,
    customer_id,
    status,
    TO_CHAR(order_date, 'YYYY-MM-DD') AS order_date
FROM
    orders
WHERE
    status = 'Shipped'
    AND salesman_id = 60
    AND EXTRACT(YEAR FROM order_date) = 2017
ORDER BY
    order_date;

Execute the above code to get the following results:

Recommended tutorial: "Oracle Tutorial》

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