The EXCEPT syntax is used to combine the analysis results of two SELECT statements, returning only the rows that exist in the first result set but not in the second.
The analysis results of each SELECT statement should have the same number of columns and the same field types to be combined.
If the SELECT result contains duplicate rows, EXCEPT retains only one instance of each.
Syntax Example
Combine two tables with only one column to get the rows that exist in table one but not in table two. Among them, the first table has two rows with values of 42 and 13, respectively; the second table has only one row with a value of 13.
