Introduction to common data types in Oracle database

Oracle database is a commonly used relational database management system that supports multiple data types to meet different needs. When using Oracle database, it is very important to understand the data types of the database. This article will introduce the commonly used data types in Oracle database, with specific code examples.

1. Numerical data type

1. NUMBER

NUMBER is the most commonly used numerical data type in Oracle database, used to store integers or floats. Points. The NUMBER data type can specify precision and range.

CREATE TABLE employees (
    employee_id NUMBER(5),
    salary NUMBER(10, 2)
);

2. INTEGER

INTEGER is used to store integer values, ranging from -2^31 to 2^31-1.

CREATE TABLE students (
    student_id INTEGER
);

2. Character data type

1. CHAR

CHAR is used to store fixed-length strings, with a maximum length of 2000 characters.

CREATE TABLE customers (
    customer_id CHAR(10),
    customer_name CHAR(50)
);

2. VARCHAR2

VARCHAR2 is used to store variable-length strings with a maximum length of 4000 characters.

CREATE TABLE products (
    product_id VARCHAR2(20),
    product_name VARCHAR2(100)
);

3. Date data type

1. DATE

DATE is used to store date and time information.

CREATE TABLE orders (
    order_id NUMBER,
    order_date DATE
);

2. TIMESTAMP

TIMESTAMP is used to store date and timestamp information.

CREATE TABLE logs (
    log_id NUMBER,
    log_time TIMESTAMP
);

4. LOB data type

LOB (Large Object) data type is used to store large amounts of text data, binary data or image data.

CREATE TABLE documents (
    document_id NUMBER,
    content CLOB
);

5. Other data types

In addition to the common data types mentioned above, Oracle database also supports some other special data types, such as BOOLEAN, BINARY_INTEGER, etc.

CREATE TABLE flags (
    flag_id NUMBER,
    is_active BOOLEAN,
    flag_value BINARY_INTEGER
);

Summary

In Oracle database, the choice of data type has a crucial impact on database design and performance. By choosing the right data types, you can improve the efficiency and reliability of your database. I hope that the common Oracle data types and corresponding code examples introduced in this article can help readers better understand and apply data type selection in database design.

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