How to use concat function in oracle

The CONCAT function in Oracle is used to connect strings: Connect multiple strings: CONCAT(string1, string2, ...) Connect strings and column values: CONCAT('text', column name) is used Operator concatenates strings: 'string1' || 'string2' || ...Note: If any string is NULL, the result is NULL; up to 254 strings can be concatenated.

Usage of CONCAT function in Oracle

Introduction
CONCAT function is used to Concatenate two or more strings. It is a built-in function and does not need to be created or loaded.

Syntax

<code>CONCAT(string1, string2, ...)</code>

Among them:

• string1, string2, etc. are the strings to be connected.

Usage
The CONCAT function can be used in the following ways:

Concatenate multiple strings:

<code>SELECT CONCAT('Hello', ' ', 'World');</code>

Output: Hello World

Concatenating strings and column values:

<code>SELECT CONCAT('Employee Name: ', employee_name);</code>

Output: Employee Name: John Doe

Concatenate strings using operators:
The CONCAT function can also be used with operators, such as ||:

<code>SELECT 'Hello' || ' ' || 'World';</code>

Output: Hello World

Additional Notes

• If any of the strings to be concatenated is NULL, the output is NULL.
• CONCAT can concatenate up to 254 strings.
• If you need to concatenate a large number of strings, you can use the DBMS_LOB.CONCAT procedure in the DBMS_LOB package.

Example
The following example demonstrates the use of the CONCAT function:

<code>SELECT CONCAT('First Name: ', first_name, ', Last Name: ', last_name) AS "Full Name"
FROM employees;</code>

Output:

Full Name

First Name: John, Last Name: Doe

First Name: Mary, Last Name : Jones

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