oracle set default value

Oracle database is an advanced and powerful database management system that has many functions and options to help database administrators better manage the database. One of them is setting default values. In this article, we will take an in-depth look at how to set default values ​​in Oracle database and explore why it is needed in real-world scenarios.

Under what circumstances do I need to set a default value?

When processing data, database administrators usually need to ensure the integrity and consistency of data tables to avoid problems such as data loss and data corruption. Setting default values ​​is an effective approach in this regard. Specifically, setting default values ​​will be very useful in the following situations:

1. For those tables that insert records with some common fields, such as date timestamp and status, we can set default values ​​to Improve insertion efficiency and accuracy.
2. For tables that need to import large amounts of data quickly, setting default values ​​can avoid errors caused by manual data entry.
3. For tables with multiple user operations, setting default values ​​can provide a consistent data input and output format for the table.

How to set default value in Oracle?

In Oracle database, setting default values ​​is simple and easy. Just follow these steps:

1. Connect to your database: Enter your credentials in a tool like SQL Plus or TOAD and connect to your database.
2. First, you need to select the table where you want to set the default value. In this example, we will set up a table called "CUSTOMERS".

SELECT * FROM CUSTOMERS;

3. Now, select the column for which you want to set a default value. In this example, we will select the "ADDRESS1" column.

SELECT ADDRESS1 FROM CUSTOMERS;

4. Now, we will run the ALTER TABLE command to set the default value. In this example we will use the default value "NO ADDRESS PROVIDED".

ALTER TABLE CUSTOMERS MODIFY ADDRESS1 DEFAULT 'NO ADDRESS PROVIDED';

5. You can also set default values ​​in table parameters. In this example, we will set the default value in the table parameter to "NO CUSTOMERS".

ALTER TABLE CUSTOMERS MODIFY (
CUSTOMER_TYPE DEFAULT 'NO CUSTOMERS'
);

Now, you have successfully set the default value. From now on, when you add a new record to the table, if no value is provided, a default value will be used for the field.

Summary

In Oracle, setting default values ​​is very useful. It can help database administrators maintain the consistency and integrity of tables, while also improving the efficiency and accuracy of inserting data. Additionally, setting defaults provides consistent data input and output formatting when working with tables for multiple users. By following the above steps, you can easily set default values ​​in Oracle database for better management of your data tables.

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