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How to understand the use of weed3-4.1Annotation sql. Aiming at this problem, this article introduces the corresponding analysis and solution in detail, hoping to help more partners who want to solve this problem to find a more simple and feasible method.

Weed3 a mini ORM framework (only 0.1Mb)

Source code: https://github.com/noear/weed3 source code: https://gitee.com/noear/weed3

Use conventions *

1. Project start compilation parameter:-parameters

First a demo// declares mapperpublic interface DbMapper1 {@ Sql ("select * from appx where app_id = @ {app_id} limit 1") AppxModel appx_get (int app_id) throws Exception;} / / using mapperDbMapper1 dm = db.mapper (DbMapper1.class); AppxModel m = dm.appx_get (1); then a little bit more complicated demo1

1. Declare a mapper

/ / added replacement character / / added cache control public interface DbMapper1 {@ Sql (value = "select * from ${tb} where app_id = @ {app_id} limit 1", caching = "test", cacheTag = "app_$ {app_id}") AppxModel appx_get (String tb, int app_id) throws Exception;}

two。 Use it

DbContext db = new DbContext (...); DbMapper1 dm = db.mapper (DbMapper1.class); AppxModel m = dm.appx_get ("appx", 1); two variable forms + cache control

Two forms of variables

${} substitution variable (equivalent to placeholder for string concatenation)

@ {} compile variables (will be compiled to? and passed to jdbc through variables)

Cache control

Caching caching service

CacheTag cache tag (on top of key, the virtual tag; is established for easy cleaning)

UsingCache cache usage time

CacheClear cache cleanup (through cacheTag cleanup)

One more demo2.

After updating, clear the cache: app_$ {app_id}

Public interface DbMapper2 {@ Sql (value = "update appx set name=@ {name} where app_id = @ {app_id}", caching = "test", cacheClear = "app_$ {app_id}") void appx_set (int app_id, String name) throws Exception;} another demo3

Use query results to build cahce tag:app_type$ {type}

Public interface DbMapper3 {@ Sql (value = "select * from appx where app_id = @ {app_id} limit 1", caching = "test", cacheTag = "app_$ {app_id}, app_type$ {type}") AppxModel appx_get (int app_id) throws Exception;} add: build a cache service / / write anywhere / / 1. Initialize an ICacheServiceEx//2. Register to the cache / / 3 through nameSet ("test"). After that, it can be used by @ sql's caching (the same is true of xml sql's caching) / / new LocalCache ("test", 60). NameSet ("test"). This is the answer to the question on how to understand weed3-4.1. start annotating sql. I hope the above content can be of some help to you. If you still have a lot of doubts to be solved, you can follow the industry information channel for more related knowledge.

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