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fix mispell

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kwongtai 2018-04-13 20:05:07 +08:00
parent f04af8ccf0
commit 7f6fefe082
1 changed files with 4 additions and 4 deletions
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notes/SQL.md
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@ -251,7 +251,7 @@ FROM mytable
| LOWER() UPPER() | 转换为小写或者大写 | | LOWER() UPPER() | 转换为小写或者大写 |
| LTRIM() RTIM() | 去除左边或者右边的空格 | | LTRIM() RTIM() | 去除左边或者右边的空格 |
| LENGTH() | 长度 | | LENGTH() | 长度 |
| SUNDEX() | 转换为语音值 | | SOUNDEX() | 转换为语音值 |
其中， **SOUNDEX()** 是将一个字符串转换为描述其语音表示的字母数字模式的算法，它是根据发音而不是字母比较。 其中， **SOUNDEX()** 是将一个字符串转换为描述其语音表示的字母数字模式的算法，它是根据发音而不是字母比较。
@ -347,7 +347,7 @@ GROUP BY col
ORDER BY num; ORDER BY num;
``` ```
WHERE 过滤行，HAVING 过滤分组。行过滤应当先与分组过滤； WHERE 过滤行，HAVING 过滤分组。行过滤应当先于分组过滤；
```sql ```sql
SELECT col, COUNT(*) AS num SELECT col, COUNT(*) AS num
@ -464,7 +464,7 @@ from employee natural join department;
```sql ```sql
select Customers.cust_id, Orders.order_num select Customers.cust_id, Orders.order_num
from Customers left outer join Orders from Customers left outer join Orders
on Customers.cust_id = Orders.curt_id; on Customers.cust_id = Orders.cust_id;
``` ```
如果需要统计顾客的订单数，使用聚集函数。 如果需要统计顾客的订单数，使用聚集函数。
@ -473,7 +473,7 @@ on Customers.cust_id = Orders.curt_id;
select Customers.cust_id, select Customers.cust_id,
COUNT(Orders.order_num) as num_ord COUNT(Orders.order_num) as num_ord
from Customers left outer join Orders from Customers left outer join Orders
on Customers.cust_id = Orders.curt_id on Customers.cust_id = Orders.cust_id
group by Customers.cust_id; group by Customers.cust_id;
``` ```