Shows how to increment multiple word counts in Postgresql using a single round trip to the database

posgresql-word-count-upsert.sql

WITH
    to_be_upserted (word, count) AS (
        VALUES
        ('fudge', 1),
        ('baz', 1),
        ('foo', 2),
        ('bar', 2),
        ('bucket', 1)
    ),
    updated AS (
        UPDATE
            word_counts
        SET
            count = word_counts.count + to_be_upserted.count
        FROM
            to_be_upserted
        WHERE
            word_counts.word = to_be_upserted.word
        RETURNING word_counts.word
    )
INSERT INTO word_counts
    SELECT * FROM to_be_upserted
    WHERE word NOT IN (SELECT word FROM updated);

Assumes you have table created like

CREATE TABLE word_count (word varchar(200) PRIMARY KEY, count integer);

based on this blog post.

As you can see in the snippet, for each value, the count is incremented by the integer component if the word already exists in the database, otherwise it is inserted.