I have seen that nearly every database entry includes a ID area which auto-batches.

Is really needed?

Otherwise, what exactly is it helpful for?

It's helpful for locating that row later. For those who have other values which are guaranteed unique for every row, you do not always need an additional id column, since make use of the other column because the primary (unique) key.

But, the benefit of the car-incrementing id column is the fact that it's
a) unique for every row, and
b) never changes.

Take StackOverflow for example. Every question comes with an ID (that one is 6886017), and uses both ID and also the title within the URL. So there may be easily two questions with similar title, as their IDs it's still unique. An you may also alter the title of the question, and old links into it will still work, because what StackOverflow is actually searching at, may be the ID area of the URL, not the title part.

No, it isn't really needed, but when a row inside a different table must reference that row, it is a reasonably great way to distinctively (unique for the reason that table, a minimum of) see that row.

It's convenient (WHERE id = 123 rather than WHERE name = 'blah' and somethingelse = 'foo') and on top of that, integer indexes are often very performant in comparison to e.g. string indexes. On top of that

When you train with relational databases you have to have the ability to distinctively identify each row. Oftentimes you are able to select one or mode data posts which will distinctively identify a row for you personally. That's known as natural key. Without having a good way to recognize each row, you'll be able to introduce your personal column with sole reason for carrying this out identification. That's known as synthetic key and that is the id column with auto increment that you're asking about.

It's not needed as lengthy as you've another way to recognize each row. It might be easy to have rows which are indistinguishable from one another but that will help reduce worth of relational database paradigm. Also it doesn't need to be auto incremented number. Frequently unique id string can be used for example UUID.

"ID" means identifier. Poor relational database design tuples (rows) inside a relation are distinctively identifiable by secrets and each relation should have a minumum of one key.

Tables without secrets would permit duplicate rows, which results in ambiguity, inaccurate results and problems properly determining the real life organizations that the rows usually are meant to describe. Secrets are thus an imporant facet of data integrity for just about any database table.

Note however that the key does not need to be just one column and nor does it need to be "auto-incrementing". Individuals features do not have anything much related to selecting good secrets for the tables.

It's not needed nevertheless it very suggested. It's very helpful to keep rows unique for indexing, up-to-date, removes, etc.

Here's some useful information: http://en.wikipedia.org/wiki/Unique_key

The ID area generally is a primary key for that area. It identifies that area for the reason that specific table, the main key cannot repeat. It is also used like a foreign answer to help join tables.

Here is a simple introduction:http://www.opensourcevarsity.com/mysqldba/l8primaryforeignkey