mysql bulk insert referring ID from another table

Question

I have two tables:

table_user
======================================
UID     UserName
1       UserA
2       UserB
3       UserC


table_score
==============================
UID     Date         Score
2       18/7/2013     100
2       19/7/2013     150

I need to bulk insert score history data (thousands of rows) to table_score. The history data consists of UserName, Date and Score only.

What I'm doing is to have my PHP script load the UID of a given UserName from MySQL, add the UID in to the bulk insert SQL and send it back to MySQL. This requires 2 communications between PHP and MySQL. And I repeat the above for another user.

Is it possible to let MySQL insert the date and score, and fill-in the UID automatically based on the given UserName in one SQL?

Answer 1

The fastest method to import massive amount of data for MySql is to use LOAD DATA INFILE

If you were to have a coma delimited file like this

"UserB","18/7/2013",100
"UserB","19/7/2013",150
"UserC","20/7/2013",140

Then you load it with a query like this

LOAD DATA LOCAL INFILE '/path/to/your/file.csv' 
INTO TABLE table_score 
   FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"' 
   LINES TERMINATED BY '\n' -- or '\r\n' if it's Windows
(@username, @date, @score) 
SET uid =  
    (
      SELECT uid 
        FROM table_user 
       WHERE username = @username
       LIMIT 1
    ),
    date = STR_TO_DATE(@date, '%d/%m/%Y'),
    score = @score;