I’d probably use a LEFT JOIN, which will return rows even if there’s no match, and then you can select only the rows with no match by checking for NULLs. So, something like: SELECT V.* FROM voter V LEFT JOIN elimination E ON V.id = E.voter_id WHERE E.voter_id IS NULL Whether that’s more or less … Read more
I think your last statement is the best way. You can also try SELECT A.* from A left join B on A.x = B.y where B.y is null
Consider the following table mysql> select * from cart ; +——+————+————-+ | id | date | total_price | +——+————+————-+ | 1 | 2014-01-01 | 10 | | 2 | 2014-01-20 | 20 | | 3 | 2014-02-03 | 30 | | 4 | 2014-02-28 | 40 | | 5 | 2014-06-01 | 50 | | … Read more
You didn’t join the table in your query. Your original query will always return nothing unless there are no records at all in eotm_dyn, in which case it will return everything. Assuming these tables should be joined on employeeID, use the following: SELECT * FROM employees e WHERE NOT EXISTS ( SELECT null FROM eotm_dyn … Read more
For an array of strings (but not an array of objects), you can check if an item exists by calling .indexOf() and if it doesn’t then just push the item into the array: var newItem = “NEW_ITEM_TO_ARRAY”; var array = [“OLD_ITEM_1”, “OLD_ITEM_2”]; array.indexOf(newItem) === -1 ? array.push(newItem) : console.log(“This item already exists”); console.log(array)