What does the column function in mysql mean?

The COLUMN() function in MySQL returns the name of the specified column in the specified table and is used to dynamically generate query strings or process metadata.

What is the COLUMN function in MySQL?

The COLUMN() function is a system function that returns the name of the specified column in the specified table.

Function syntax:

<code class="SQL">COLUMN(column_name)</code>

Where:

• column_name is the name of the column whose name is to be returned.

Usage:

The COLUMN() function is most commonly used to dynamically generate SQL query strings or process metadata. For example:

<code class="SQL">SELECT COLUMN() FROM table_name;</code>

The above query will return the names of all columns in table table_name.

<code class="SQL">ALTER TABLE table_name CHANGE COLUMN OLD_NAME NEW_NAME INT;</code>

The above query uses the COLUMN() function to change the name of column OLD_NAME in table table_name to NEW_NAME.

Note:

• The name returned by the COLUMN() function is case-sensitive.
• The COLUMN() function can only be used on a single column.

The above is the detailed content of What does the column function in mysql mean?. For more information, please follow other related articles on the PHP Chinese website!