限制資料

Oracle SQL 入門

Sara Billen

Curriculum Manager

篩選列

比較運算子
比較關鍵字
邏輯運算子

WHERE

SELECT FirstName, LastName, Country 
FROM Customer
WHERE Country = 'Portugal'

| FirstName | LastName  | Country  |
|-----------|-----------|----------|
| João      | Fernandes | Portugal |
| Madalena  | Sampaio   | Portugal |

比較運算子

運算子	說明
>	大於
>=	大於或等於
<	小於
<=	小於或等於
=	等於
<>	不等於

SELECT UnitPrice
FROM Track
WHERE UnitPrice <> 0.99

比較關鍵字

WHERE 子句進階功能

比較關鍵字 - BETWEEN

SELECT Name, Milliseconds 
FROM Track
WHERE Milliseconds BETWEEN 100000 AND 200000

| Name              | Milliseconds |
|-------------------|--------------|
| Perfect           | 188133       |
| Right Through You | 176117       |
| We Die Young      | 152084       |
| Put You Down      | 196231       |
| ...                              |

比較關鍵字 - IN

SELECT EmployeeId, LastName, Title
FROM Employee
WHERE EmployeeId IN (4, 5, 6)

| EmployeeId | LastName | Title               |
|------------|----------|---------------------|
| 4          | Park     | Sales Support Agent |
| 5          | Johnson  | Sales Support Agent |
| 6          | Mitchell | IT Manager          |

比較關鍵字 - LIKE

使用 LIKE 依字元樣式選取相符的列

符號	說明
`%`	代表任意長度（含 0）的字元序列
`_`	代表任意單一字元

比較關鍵字 - LIKE

SELECT LastName
FROM Employee
WHERE LastName LIKE '_a%'

| LastName |
|----------|
| Park     |
| Callahan |

邏輯運算子

邏輯運算子 - AND

SELECT InvoiceId, BillingCountry, Total
FROM Invoice
WHERE BillingCountry = 'Australia' 
      AND Total > 4

| InvoiceId | BillingCountry | Total |
|-----------|----------------|-------|
| 66        | Australia      | 5.94  |
| 250       | Australia      | 13.86 |
| 305       | Australia      | 8.91  |

邏輯運算子 - OR

SELECT InvoiceId, BillingCountry, Total
FROM Invoice
WHERE BillingCountry = 'Australia' 
      OR Total > 4

| InvoiceId | BillingCountry | Total |
|-----------|----------------|-------|
| 3         | Belgium        | 5.94  |
| 4         | Canada         | 8.91  |
| 5         | USA            | 13.86 |
| 10        | Ireland        | 5.94  |
| ...                                |

邏輯運算子 - NOT

SELECT InvoiceId, BillingCountry, Total
FROM Invoice
WHERE BillingCountry NOT IN ('Australia', 'Canada', 'United Kingdom')

| InvoiceId | BillingCountry | Total |
|-----------|----------------|-------|
| 1         | Germany        | 1.98  |
| 2         | Norway         | 3.96  |
| 3         | Belgium        | 5.94  |
| 5         | USA            | 13.86 |
| ...                                |

重點整理

WHERE：依條件篩選列

比較運算子：=、<、>、<=、>=、<>
比較關鍵字：BETWEEN、IN、LIKE
邏輯運算子：AND、OR、NOT

一起來練習吧！

Oracle SQL 入門