Listing 11 USES the value of col2 as a parameter to restrict DELETE operations based on the value of an XML element (the zip or zip code element of a client's address).
Case sensitivity is sometimes difficult for SQL programmers to remember, as SQL query syntax permits them to use "zip," "zip," and "zip" to refer to the same column name.
SQL程序员有时候很难记住大小写敏感这一点,因为SQL查询语法允许使用“ zip ”、“ zip ”和“ zip ”来引用同一个列名。