How to write an oracle creation form

Create a table in Oracle through the following steps: 1. Use the CREATE TABLE statement. 2. Define the table name. 3. Specify columns and their data types and constraints (such as NOT NULL, UNIQUE). 4. Define the primary key (optional). 5. Add constraints (such as foreign keys, check constraints) (optional).

Create a table in Oracle

Creating tables in Oracle databases is a basic operation for storing and managing data. To create a table, you can do it by following the steps:

1. Use CREATE TABLE statement

 <code class="sql">CREATE TABLE  (   [NOT NULL] [UNIQUE],   [NOT NULL] [UNIQUE], ...   [NOT NULL] [UNIQUE] );</code>

2. Define the table name

is the name of the new table to be created.

3. Specify columns

• : The name of the column.
• : The data type of the column (such as VARCHAR2, NUMBER, DATE, etc.).
• NOT NULL : The specified column cannot be empty.
• UNIQUE : The value in the specified column must be unique.

4. Define the primary key

One or more columns can be specified as primary keys to uniquely identify each row in the table. To define a primary key, you can add a PRIMARY KEY constraint to the column definition.

 <code class="sql">CREATE TABLE  (   PRIMARY KEY, ... );</code>

5. Add constraints

Constraints are used to enforce data integrity rules. In addition to NOT NULL and UNIQUE constraints, other constraints can also be added, such as foreign keys, check constraints, etc.

Example:

To create a table named customers that contains customer_id (primary key), name , and address columns, you can use the following statement:

 <code class="sql">CREATE TABLE customers ( customer_id NUMBER PRIMARY KEY, name VARCHAR2(50) NOT NULL, address VARCHAR2(255) );</code>

Notice:

• Table and column names are case-insensitive.
• The NOT NULL constraint ensures that the column cannot contain null values.
• UNIQUE constraints ensure that values ​​in columns are unique.

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