In a SQL join, if we ignore the last record because it hasn't joined, will we get only three records for gate 4?

When performing a join in SQL, the result set depends on the type of join used. An INNER JOIN returns only rows that have matching keys in both tables; rows that do not match are omitted. If you have a table with four rows and one of them has no matching key in the other table, an INNER JOIN will return only the three matching rows. A LEFT (or RIGHT) OUTER JOIN, however, includes all rows from the left (or right) table and fills NULLs for missing matches. If you want to ignore the unmatched row, you would use an INNER JOIN or apply a WHERE clause to filter out NULLs. Therefore, if you are using an INNER JOIN and one record has no match, you will indeed get only three records in the result set for that gate. If you need to keep the unmatched row but still identify it, use a LEFT JOIN and check for NULLs in the joined columns.