If they have, a variable is created and constructed to contain all the values included in the form.
如果这些字段都填写好了，则创建一个变量，并使该变量包含表单中包括的所有值。
2
When the BULK COLLECT clause is included, the statement can return multiple rows; the variable in the INTO clause must be an array, and each row is stored in an array element.
The var attribute causes the content fetched from the specified URL to be stored (as a String value) in a scoped variable, rather than included in the current JSP page.
var 属性会导致从指定 URL 获取的内容（作为 String 值）被存储在一个限定了作用域的变量中，而不是包含在当前 JSP 页面中。