将数据插入第一个空列单元格而不创建新行

I want to add data to a table, one column at a time. Therefore I don't want to always add a new row, as the column I'm adding to may not have much data in compared to the other columns. As a result I suppose I want to add the data to the first empty cell in the specified column without necessarily adding a new row to the whole table (as there may already be enough rows).

My table has 5 columns.

I'm currently using:

$sql=("INSERT INTO [MY_TABLE] ([MY_COLUMN]) VALUES ('[MY_DATA]')");

Please could someone assist with the correct code? I know it's basic stuff but I'm new to mySQL.

Thanks in advance.

So you can use UPDATE statement with a WHERE condition to target that specific row

UPDATE table_name SET column_name = 'whatever' WHERE column_name = '' AND id = '1'

If you want to update all rows where that column is blank than simply use

UPDATE table_name SET column_name = 'whatever' WHERE column_name = ''

no need of using id in above query

Reference on UPDATE