70 lines
2.7 KiB
Markdown
70 lines
2.7 KiB
Markdown
|
---
|
||
|
|
title: SQL Where Clause
|
||
|
|
---
|
||
|
|
|
||
|
|
## SQL Where Clause
|
||
|
|
|
||
|
|
### `WHERE` Clause (and/or, `IN`, `BETWEEN`, and `LIKE`)
|
||
|
|
|
||
|
|
The `WHERE` clause is used to limit the number of rows returned.
|
||
|
|
|
||
|
|
In this case all five of these will be used is a some what ridiculous `WHERE` clause.
|
||
|
|
|
||
|
|
Here is the current full student list to compare to the `WHERE` clause result set:
|
||
|
|
|
||
|
|
```sql
|
||
|
|
select studentID, FullName, sat_score, rcd_updated from student;
|
||
|
|
```
|
||
|
|
|
||
|
|
```text
|
||
|
|
+-----------+------------------------+-----------+---------------------+
|
||
|
|
| 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....
|
||
|
|
|
||
|
|
* `WHERE` Student IDs are between 1 and 5 (inclusive)
|
||
|
|
* `OR` studentID = 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:
|
||
|
|
|
||
|
|
```sql
|
||
|
|
|
||
|
|
select studentID, FullName, sat_score, recordUpdated
|
||
|
|
from student
|
||
|
|
where (studentID between 1 and 5 or studentID = 8)
|
||
|
|
and
|
||
|
|
sat_score NOT in (1000, 1400);
|
||
|
|
```
|
||
|
|
|
||
|
|
```text
|
||
|
|
+-----------+----------------------+-----------+---------------------+
|
||
|
|
| 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.
|
||
|
|
|
||
|
|
I hope this at least gives you enough to get started.
|
||
|
|
|
||
|
|
Please see the manual for your database manager and have fun trying different options yourself.
|