UNION SQL and the Potential for SQL Injection
SQL is a powerful language for manipulating relational databases. The UNION operator provides a useful function for combining the results of multiple SELECT statements into a single result set. However, if misused, UNION can lead to a security risk called SQL injection. What is UNION SQL? UNION is helpful when you want to combine similar data from different tables. For example, if you want to get the names and cities from both the customer and employee tables, you can write: ...