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MySQL - 更新最后一次出现的字符串(MySQL - Update last occurrence of string)

 我有这样一张桌子：  
 +----------------------------+
 | id    | name     |  helper |
 +----------------------------+
 |    1  | user1    |    NULL |
 |    2  | user1    |    NULL |
 |    3  | user1    |    NULL |
 |    4  | user2    |    NULL |
 |    5  | user2    |    NULL |
 +----------------------------+
 
 现在我想更新“user1”的最后一次出现 - 我该怎么做？  
 这是我现在的示例查询：  
    UPDATE Table SET helper = 'bob' WHERE name = 'user1' AND helper IS NULL;
 
 但是，这会更新所有“user1”条目。  
 提前致谢。 

I have a table like this: 
 +----------------------------+
 | id    | name     |  helper |
 +----------------------------+
 |    1  | user1    |    NULL |
 |    2  | user1    |    NULL |
 |    3  | user1    |    NULL |
 |    4  | user2    |    NULL |
 |    5  | user2    |    NULL |
 +----------------------------+
 
Now I want to update the LAST occurrence of "user1" - how do I do that? 
This is my example query right now: 
    UPDATE Table SET helper = 'bob' WHERE name = 'user1' AND helper IS NULL;
 
However, this updates all the "user1" Entries. 
Thanks in advance.

原文：https://stackoverflow.com/questions/24215526

更新时间：2022-03-02 06:03

最满意答案

 NVM，没有odbc接口，但它是DBI之类的（看到DBI不使用odbc，除了在DBD :: ODBC中）  
 libdbi - http://libdbi.sourceforge.net/  
 
  libdbi在C中实现了一个与数据库无关的抽象层，类似于Perl中的DBI / DBD层。 编写一组通用代码，程序员可以使用此框架利用多个数据库的强大功能和多个同步数据库连接。  
  为了利用libdbi框架，您需要为特定类型的数据库安装驱动程序。 libdbi正式支持的驱动程序分为libdbi-drivers项目。 当前版本的libdbi（0.8.3）应该适用于任何0.8.x版本的libdbi-drivers。 目前支持以下数据库引擎：  
 * Firebird/Interbase
* FreeTDS (provides access to MS SQL Server and Sybase)
* MySQL
* PostgreSQL
* SQLite/SQLite3
 

NVM, no odbc interface, but it is DBI like (seeing as DBI doesn't use odbc except in DBD::ODBC) 
libdbi - http://libdbi.sourceforge.net/  
 
 libdbi implements a database-independent abstraction layer in C, similar to the DBI/DBD layer in Perl. Writing one generic set of code, programmers can leverage the power of multiple databases and multiple simultaneous database connections by using this framework. 
 In order to utilize the libdbi framework, you need to install drivers for a particular type of database. The drivers officially supported by libdbi are split off into the libdbi-drivers project. The current version of libdbi (0.8.3) is supposed to work with any 0.8.x release of libdbi-drivers. Currently the following database engines are supported: 
 * Firebird/Interbase
* FreeTDS (provides access to MS SQL Server and Sybase)
* MySQL
* PostgreSQL
* SQLite/SQLite3

MySQL - 更新最后一次出现的字符串(MySQL - Update last occurrence of string)

最满意答案

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