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mysql中怎么批量导入和批量删除？？？

时间：2010-06-02

来源：互联网

代码:

+-----------------------------------------------+--------------------+
| name | parent_category_id |
+-----------------------------------------------+--------------------+
| Contents | 0 |
| Geographic | 0 |
| GeometryCollection properties | 1 |
| Geometry constructors | 31 |
| Geometry properties | 31 |
| Geometry relations | 31 |
| LineString properties | 31 |
| MBR | 31 |
| Point properties | 31 |
| Polygon properties | 31 |
| WKB | 31 |
| WKT | 31 |
| Account Management | 32 |
| Administration | 32 |
| Compound Statements | 32 |
| Data Definition | 32 |
| Data Manipulation | 32 |
| Data Types | 32 |
| Functions | 32 |
| Functions and Modifiers for Use with GROUP BY | 32 |
| Geographic Features | 32 |
| Language Structure | 32 |
| Table Maintenance | 32 |
| Transactions | 32 |
| User-Defined Functions | 32 |
| Utility | 32 |
| Bit Functions | 35 |
| Comparison operators | 35 |
| Control flow functions | 35 |
| Date and Time Functions | 35 |
| Encryption Functions | 35 |
| Information Functions | 35 |
| Logical operators | 35 |
| Miscellaneous Functions | 35 |
| Numeric Functions | 35 |
| String Functions | 35 |
+-----------------------------------------------+--------------------+

name列取第一个字符，并分组count. 把count数大于等于3的那个字母对应的数据（即以这个字符开头的数据）全部输出来.
表是用的mysql中的help_category数据表.

作者: rufen 发布时间: 2010-06-02

没有明白楼主的意思。

作者: shinery 发布时间: 2010-06-02

代码:

select * from help_category where left(name,1) in (select left(name,1) from help_category group by left(name,1) having count(parent_category_id) > 2 ) order by left(name,1);

试出来了 o(∩_∩)o...哈哈

作者: rufen 发布时间: 2010-06-02

代码:

+------------------+-------------------------------+--------------------+-----+
| help_category_id | name | parent_category_id | url |
+------------------+-------------------------------+--------------------+-----+
| 6 | Control flow functions | 35 | |
| 32 | Contents | 0 | |
| 16 | Comparison operators | 35 | |
| 21 | Compound Statements | 32 | |
| 36 | Data Definition | 32 | |
| 25 | Data Manipulation | 32 | |
| 29 | Date and Time Functions | 35 | |
| 19 | Data Types | 32 | |
| 31 | Geographic Features | 32 | |
| 33 | Geometry properties | 31 | |
| 28 | Geometry relations | 31 | |
| 23 | GeometryCollection properties | 1 | |
| 22 | Geometry constructors | 31 | |
| 1 | Geographic | 0 | |
| 27 | Language Structure | 32 | |
| 12 | Logical operators | 35 | |
| 11 | LineString properties | 31 | |
+------------------+-------------------------------+--------------------+-----+

结果如上

作者: rufen 发布时间: 2010-06-02

select * from help_category where substr(name, 1,1 ) in (select substr(name, 1, 1) FROM help_category group by substr(name, 1, 1) having count(substr(name, 1, 1) ) >= 3)

作者: tingjie 发布时间: 2010-06-02

牛叉，执行这样一条语句要多少时间

作者: shinery 发布时间: 2010-06-02

学习下