mysql insert race condition

Question

How do you stop race conditions in MySQL? the problem at hand is caused by a simple algorithm:

1. select a row from table
2. if it doesn\'t exist, insert it

Answer 1

In case insert ignore doesnt fit for you as suggested in the accepted answer , so according to the requirements in your question :

1] select a row from table
2] if it doesn't exist, insert it

Another possible approach is to add a condition to the insert sql statement, e.g :

INSERT INTO table_listnames (name, address, tele)
SELECT * FROM (SELECT 'Rupert', 'Somewhere', '022') AS tmp
WHERE NOT EXISTS (
    SELECT name FROM table_listnames WHERE name = 'Rupert'
) LIMIT 1;

Reference: https://stackoverflow.com/a/3164741/179744