共找到 310 与true 相关的结果，耗时6 ms
选择运算(σ)：σF(R)={t|t∈R∧F(t)=TRUE}选择运算是对一个二维表按条件F进行横向选择，从R中选择出若干元组(行)，其中F是一个逻辑表达式，其值为“真”或“假”，如“课号=“C12”∧成绩＞80”可以用检索选修了G12课程并且成绩大于80分的学生数据。投影运算(π)：πA(R)=
Which of the following is true of the Hatches?A .They had their children during the Great Depression.B. They left the family farm to live in an old h
Which of the following is true according to the text?A. The court is in charge of removing dangerous product.B. New products are more likely to be qu
DIt is true that good writers rewrite and rewrite and then rewrite some more. But in order to work up the desire to rewrite, it is important to learn
His first book next month is based on a true story. ( )A. publishedB. to be publishedC. to publishD. being published
Which of the following can best explain Judy Garland’s words?A. Be your true self rather than follow others.B. Don’t copy others or you can’t be the
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