Question

In my current project I’m trying to check a MySQL database: a MySQL database is updated by another program, so my C++ program needs to select only the new rows. It is not going to be a small table (>10000 rows), so I do not want to search each row. i.e. checking a column like isNew=0 or =1. I already found:

Query to find tables modified in the last hour

http://www.codediesel.com/mysql/how-to-check-when-a-mysql-table-was-last-updated/

However, in this example you can only get the table which is updated. How can I only select the new rows from a table?

Answer 1

I would recommend adding an isNew column to the table with default value 1 and add an index on it. The index will prevent your query from checking all rows. After you have processed the row, set isNew to 0.