file_read
1. FILE_READ Function
=======file_read
1. FILE_READ Function
>>>>>>> 9d19b1c8cb744c8e86d5c15b74d8b5f719ad62beThe FILE_READ function in H2 database is used to read the content of a file and return it as a string.
2. Syntax
The syntax for the FILE_READ function in H2 database is as follows:
FILE_READ(filename)
Arguments
filename
: The name or path of the file to be read. It should be a string value specifying the file location.
Return
- The FILE_READ function returns the content of the file as a string.
3. Notes
- The FILE_READ function in H2 database reads the content of a file from the file system. It requires the necessary file system permissions to access the file.
- The file should be accessible to the H2 database server. The path can be relative or absolute, depending on the file's location.
- If the file does not exist or cannot be read, the FILE_READ function will return
NULL
. - Ensure that the file is closed properly after reading to avoid resource leaks.
4. Examples
Here are a few examples demonstrating the usage of the FILE_READ function in H2 database:
Example 1 - Reading the content of a file:
SELECT FILE_READ('/path/to/file.txt') AS file_content;
Output:
file_content
--------------------------
This is the file content.
It has multiple lines.
Example 2 - Reading the content of a file specified in a column:
CREATE TABLE files (
id INT PRIMARY KEY,
filepath VARCHAR(255)
);
INSERT INTO files VALUES (1, '/path/to/file1.txt'), (2, '/path/to/file2.txt');
SELECT id, filepath, FILE_READ(filepath) AS file_content
FROM files;
Output:
id | filepath | file_content
---+-----------------------+-------------------------------
1 | /path/to/file1.txt | This is the content of file 1.
2 | /path/to/file2.txt | This is the content of file 2.
5. Related Functions
- file_write - Write content to a file.