Database Reference
In-Depth Information
Inserts, updates, and upserts
So far, we've used the
INSERT
statements to add new rows to our tables, and the
UPDATE
statements to update information in existing rows. As it turns out, both
INSERT
and
UPDATE
statements can modify existing rows and can create new rows. At their core, we
can most accurately think of the
INSERT
and
UPDATE
statements as providing different
syntax for the same underlying operation, an
upsert
.
This is quite astonishing for those of us who are used to SQL, in which the
INSERT
and
UPDATE
statements are entirely distinct. While there are some situations in which upsert
behavior is quite handy, it can also be a stumbling block, especially for developers who are
new to Cassandra. Fortunately, Cassandra offers us ways to ensure that our write operations
behave the way we intend; we'll explore these techniques after taking a closer look at up-
serts.
