How to understand the use of weed3-4.1commenting sql
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.
