What does FILENAME mean in sql

The meaning of FILENAME in SQL

In SQL, the FILENAME function returns a string of file path and file name.

Syntax:

<code class="sql">FILENAME(<file_expression>)</code>

Where:

• <file_expression> is a return file path and file name expression.

Use Case:

The FILENAME function can be used to:

• Get the full path and filename of a file.
• Determine whether the file exists.
• Load the file contents into the table.

Example:

<code class="sql">-- 获取文件的完整路径和文件名
SELECT FILENAME('my_file.txt');

-- 检查文件是否存在
SELECT CASE WHEN FILENAME('my_file.txt') IS NOT NULL THEN 'File exists' ELSE 'File does not exist' END;

-- 将文件内容加载到表中
CREATE TABLE my_table AS
SELECT *
FROM OPENROWSET(BULK 'my_file.csv', FORMAT = 'CSV');</code>

Note:

• FILENAME function only applies to file systems document.
• The file name returned by the FILENAME function includes the extension.
• The FILENAME function returns NULL if the supplied file expression is invalid.

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