如果不存在，将条目添加到数据库的最快方法

Question

I want to add set of entries to MySQL DB table. I need to add entry if it doesn't exist, and otherwise send some signal outside that it wasn't added (fe return false).

I can check if entry exists (with one query) and add it if not exists with another. However, cause there may be thousands of entries I need to add, I think that extra query is not good.

Can I somehow use just one MySQL query, that would add entry if it doesn't exist and return false if it exists?

Answer 1

You could use WHERE NOT EXIST syntax:

INSERT INTO table (name, address, tele)
VALUES ('John', 'Somewhere', '001')
WHERE NOT EXISTS (
    SELECT name FROM table WHERE name='value'
);

Answer 2

To optimize query using WHERE NOT/EXIST queries with insert, you can do it like this:

INSERT INTO table (name, address, tele)
VALUES ('John', 'Somewhere', '001')
WHERE NOT EXISTS (
    SELECT 1 FROM table WHERE name='value'
);

Which can be further optimize using LIMIT 1 like:

INSERT INTO table (name, address, tele)
VALUES ('John', 'Somewhere', '001')
WHERE NOT EXISTS (
    SELECT 1 FROM table WHERE name='value' LIMIT 1
);

Note: SELECT 1 is faster that SELECT [column_name]...