这个示例展示,尽管不足以创建一行,但我们必须通过设置操作符(:)来包含它的定义。
Include WHERE clause predicates for every column on the row to see if each column value is the same as its original value.在行的每个列中包含where子句谓词,来确定每列的值是否与其初始值相同。
Add a row for each of the following and include them in the estimate.为下面的每一项在表中添加一行,并把它们包含入估算之中。