sql limit子句

什么是SQL Where子句？ (What is a SQL Where Clause?)

WHERE子句(和/或IN ， BETWEEN和LIKE ) (The WHERE ?Clause (and/or, ?IN , ?BETWEEN , and ?LIKE ))

The ?WHERE ?clause is used to limit the number of rows returned.

WHERE子句用于限制返回的行數。

In this case all five of these will be used is a some what ridiculous ?WHERE ?clause.

在這種情況下，將使用所有這五個荒謬的WHERE子句。

Here is the current full student list to compare to the ?WHERE ?clause result set:

這是當前的完整學生列表，可與WHERE子句結果集進行比較：

select studentID, FullName, sat_score, rcd_updated from student;

+-----------+------------------------+-----------+---------------------+
| studentID | FullName               | sat_score | rcd_updated         |
+-----------+------------------------+-----------+---------------------+
|         1 | Monique Davis          |       400 | 2017-08-16 15:34:50 |
|         2 | Teri Gutierrez         |       800 | 2017-08-16 15:34:50 |
|         3 | Spencer Pautier        |      1000 | 2017-08-16 15:34:50 |
|         4 | Louis Ramsey           |      1200 | 2017-08-16 15:34:50 |
|         5 | Alvin Greene           |      1200 | 2017-08-16 15:34:50 |
|         6 | Sophie Freeman         |      1200 | 2017-08-16 15:34:50 |
|         7 | Edgar Frank "Ted" Codd |      2400 | 2017-08-16 15:35:33 |
|         8 | Donald D. Chamberlin   |      2400 | 2017-08-16 15:35:33 |
|         9 | Raymond F. Boyce       |      2400 | 2017-08-16 15:35:33 |
+-----------+------------------------+-----------+---------------------+
9 rows in set (0.00 sec)

Rows will be presented that…

將顯示以下行：

• WHERE ?Student IDs are between 1 and 5 (inclusive)

  WHERE學生ID是1和5(含)之間

• OR ?studentID = 8

  OR學生ID = 8

Here’s an updated query, where any record that has an SAT score that’s in this list (1000, 1400) will not be presented:

這是一個更新的查詢，其中不會顯示此列表中(1000，1400)具有SAT分數的任何記錄：

select  studentID, FullName, sat_score, recordUpdated
from    student
where   (studentID between 1 and 5 or studentID = 8)andsat_score NOT in (1000, 1400);

+-----------+----------------------+-----------+---------------------+
| studentID | FullName             | sat_score | rcd_updated         |
+-----------+----------------------+-----------+---------------------+
|         1 | Monique Davis        |       400 | 2017-08-16 15:34:50 |
|         2 | Teri Gutierrez       |       800 | 2017-08-16 15:34:50 |
|         4 | Louis Ramsey         |      1200 | 2017-08-16 15:34:50 |
|         5 | Alvin Greene         |      1200 | 2017-08-16 15:34:50 |
|         8 | Donald D. Chamberlin |      2400 | 2017-08-16 15:35:33 |
+-----------+----------------------+-----------+---------------------+
5 rows in set (0.00 sec)

*As with all of these SQL things there is MUCH MORE to them than what’s in this introductory guide.

*與所有這些SQL事物一樣，它們比本入門指南中的內容要多得多。

I hope this at least gives you enough to get started.

我希望這至少能給您足夠的入門。

Please see the manual for your database manager and have fun trying different options yourself.

請參閱數據庫管理員的手冊，并嘗試自己嘗試其他選項，這很有趣。

翻譯自: https://www.freecodecamp.org/news/the-sql-where-clause-explained/

sql limit子句