Reads file as a String. The file content is not parsed, so any information is read as one string and placed into the specified column.
path— The relative path to the file from user_files_path. Path to file support following wildcards:
'abc', 'def'— strings.
Inserting data from files a.txt and b.txt into a table as strings:
INSERT INTO table SELECT file('a.txt'), file('b.txt');