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The table "t1" has three columns: "id," "name," and "salary." If "t1" represents a forum's posting information table, where "id" is the poster's ID, "name" is the post's title, and "salary" is the score awarded for each post on the forum. The statement to display how many posts each member has made is:
A. select id, count(name) from t1 group by id;
B. select id, count(name) from t1 group by id having count(name)>5;
C. select id, count(name) from t1 group by id having count(name)>5 order by count(name);
D. select id, count(name) from t1 where id > 100 group by id;
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The goal is to display the number of posts made by each member, so you need to use "group by id" to group by member ID and then count the number of "name" entries.

正確答案是:A: `select id, count(name) from t1 group by id;`

### 專業(yè)分析:
1. **A: `select id, count(name) from t1 group by id;`**
- 這條SQL語(yǔ)句的功能是按用戶ID分組,并統(tǒng)計(jì)每個(gè)用戶發(fā)布的帖子數(shù)量。
- `group by id` 用于將數(shù)據(jù)按用戶ID進(jìn)行分組。
- `count(name)` 用于統(tǒng)計(jì)每個(gè)分組中帖子的數(shù)量。
- 這正是問(wèn)題所要求的功能:顯示每個(gè)成員發(fā)布了多少帖子。

2. **B: `select id, count(name) from t1 group by id having count(name)>5;`**
- 這條SQL語(yǔ)句除了按用戶ID分組并統(tǒng)計(jì)每個(gè)用戶發(fā)布的帖子數(shù)量外,還增加了一個(gè)條件:只顯示發(fā)布帖子數(shù)量大于5的用戶。
- 雖然這條語(yǔ)句可以統(tǒng)計(jì)帖子數(shù)量,但它并不符合問(wèn)題的要求,因?yàn)樗^(guò)濾掉了帖子數(shù)量少于或等于5的用戶。

3. **C: `select id, count(name) from t1 group by id having count(name)>5 order by count(name);`**
- 這條SQL語(yǔ)句與B類似,增加了一個(gè)排序功能:按帖子數(shù)量進(jìn)行排序。
- 同樣,它也不符合問(wèn)題的要求,因?yàn)樗^(guò)濾掉了帖子數(shù)量少于或等于5的用戶。

4. **D: `select id, count(name) from t1 where id > 100 group by id;`**
- 這條SQL語(yǔ)句在按用戶ID分組并統(tǒng)計(jì)每個(gè)用戶發(fā)布的帖子數(shù)量之前,增加了一個(gè)條件:只統(tǒng)計(jì)用戶ID大于100的用戶。
- 這也不符合問(wèn)題的要求,因?yàn)樗唤y(tǒng)計(jì)了部分用戶。

綜上所述,選項(xiàng)A是最符合問(wèn)題要求的SQL語(yǔ)句。