Question

I have 3 tables on my SQLite db as follow:

TABLE first_names

id
name
gender

TABLE last_names

id
name

TABLE names

id
first
last
gender
birthday (null)
used (default 0)

Where first and last are unique and also have a index with both being unique on the names table.

In order to fed names table I have used the below query, which worked the first time but after I had added a new name to the last_names and tried to use it again it failed.

INSERT INTO names (first, last, gender) 
       SELECT f.name AS first, l.name AS last, f.gender AS gender 
              FROM first_names f 
              LEFT JOIN last_names l 
              WHERE f.name NOT IN (SELECT first FROM names) AND 
                    l.name NOT IN (SELECT last FROM names)

Have also tried using (first, last, gender, [birthday], [used]) with values as null AS [birthday], 0 AS [used] but since it birthday is set to null on the table design and used to 0 as default and it worked on the first time didnt think it would be needed nor it made any difference anyway.

I would think it is because of the unique fields however I do have a WHERE to make sure the names are not already in the table names.

I have tried the query using C# and SQLiteAdmin both executing without requesting result or else it doesnt work.

What is wrong with my query and why it only works once ?

Answer 1

Try using:
WHERE NOT EXISTS ( SELECT * FROM names n WHERE n.first=f.name AND n.last=l.name)