From a4d018b86fb088201482e5cf5bd93e738b95f49f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=BC=80=E6=BA=90=E6=B5=B7=E5=93=A5?= <fuhai999@gmail.com>
Date: Sat, 4 Mar 2023 17:36:57 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=20"=E9=80=BB=E8=BE=91?=
 =?UTF-8?q?=E5=88=A0=E9=99=A4"=20=E7=9A=84=E6=96=87=E6=A1=A3?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/zh/logic_delete.md                       | 58 +++++++++++++++++++
 .../java/com/mybatisflex/test/Account.java    | 13 +++++
 .../mybatisflex/test/AccountSqlTester.java    | 12 +++-
 3 files changed, 82 insertions(+), 1 deletion(-)
 create mode 100644 docs/zh/logic_delete.md

diff --git a/docs/zh/logic_delete.md b/docs/zh/logic_delete.md
new file mode 100644
index 00000000..56f5a0b2
--- /dev/null
+++ b/docs/zh/logic_delete.md
@@ -0,0 +1,58 @@
+# 逻辑删除
+
+## 逻辑删除简介
+
+逻辑删除指的是在删除数据的时候，并非真正的去删除，而是将表中列所对应的状态字段（status）做修改操作，
+实际上并未删除目标数据。
+
+我们可以在做表的字段设计的时候，用一个列表标识该数据的 "删除状态"，在 mybatis-flex 中，正常状态的值为 0， 已删除
+的值为 1。
+
+## Mybatis-Flex 逻辑删除示例
+
+假设在 tb_account 表中，存在一个为 is_deleted 的字段，用来标识该数据的逻辑删除，那么 tb_account 表
+对应的 "Account.java" 实体类应该配置如下：
+
+```java
+
+@Table("tb_account")
+public class Account {
+
+    @Column(isLogicDelete = true)
+    private Boolean isDelete;
+    
+    //Getter Setter...
+}
+```
+
+此时，当我们执行如下的删除代码是：
+
+```java
+accountMapper.deleteById(1);
+```
+Mybatis 执行的 SQL 如下：
+
+```sql
+UPDATE `tb_account` SET `is_delete` = 1 
+WHERE `id` = ? AND `is_delete` = 0
+```
+可以看出，当执行 deleteById 时，Mybatis 只是进行了 update 操作，而非 delete 操作。
+
+## 注意事项
+
+当 "tb_account" 的数据被删除时（ is_delete = 1 时），我们通过 Mybatis-Flex 的 selectOneById 去查找数据时，会查询不到数据。
+原因是 `selectOneById` 会自动添加上 `is_delete = 0` 条件，执行的 sql 如下：
+
+```java
+SELECT * FROM tb_account where id = ? and is_delete = 0
+```
+
+不仅仅是 selectOneById 方法会添加 `is_delete = 0` 条件，BaseMapper 的以下方法也都会添加该条件：
+
+- selectOneByMap
+- selectOneByQuery
+- selectListByIds
+- selectListByMap
+- selectListByQuery
+- selectCountByQuery
+- paginate
\ No newline at end of file
diff --git a/mybatis-flex-core/src/test/java/com/mybatisflex/test/Account.java b/mybatis-flex-core/src/test/java/com/mybatisflex/test/Account.java
index cf4d3917..43d40ea9 100644
--- a/mybatis-flex-core/src/test/java/com/mybatisflex/test/Account.java
+++ b/mybatis-flex-core/src/test/java/com/mybatisflex/test/Account.java
@@ -1,5 +1,6 @@
 package com.mybatisflex.test;
 
+import com.mybatisflex.annotation.Column;
 import com.mybatisflex.annotation.Id;
 import com.mybatisflex.annotation.Table;
 
@@ -21,6 +22,10 @@ public class Account {
 
     private boolean isNormal;
 
+    @Column(isLogicDelete = true)
+    private Boolean isDelete;
+
+
     public Long getId() {
         return id;
     }
@@ -68,4 +73,12 @@ public class Account {
     public void setNormal(boolean normal) {
         isNormal = normal;
     }
+
+    public Boolean getDelete() {
+        return isDelete;
+    }
+
+    public void setDelete(Boolean delete) {
+        isDelete = delete;
+    }
 }
diff --git a/mybatis-flex-core/src/test/java/com/mybatisflex/test/AccountSqlTester.java b/mybatis-flex-core/src/test/java/com/mybatisflex/test/AccountSqlTester.java
index b7dbaa22..8d0366fe 100644
--- a/mybatis-flex-core/src/test/java/com/mybatisflex/test/AccountSqlTester.java
+++ b/mybatis-flex-core/src/test/java/com/mybatisflex/test/AccountSqlTester.java
@@ -1,9 +1,11 @@
 package com.mybatisflex.test;
 
-import com.mybatisflex.core.dialect.IDialect;
 import com.mybatisflex.core.dialect.CommonsDialectImpl;
+import com.mybatisflex.core.dialect.IDialect;
 import com.mybatisflex.core.querywrapper.CPI;
 import com.mybatisflex.core.querywrapper.QueryWrapper;
+import com.mybatisflex.core.table.TableInfo;
+import com.mybatisflex.core.table.TableInfos;
 import org.junit.Test;
 
 import java.util.Arrays;
@@ -158,6 +160,14 @@ public class AccountSqlTester {
         System.out.println(sql);
     }
 
+    @Test
+    public void testDeleteSql() {
+        IDialect dialect = new CommonsDialectImpl();
+        TableInfo tableInfo = TableInfos.ofEntityClass(Account.class);
+        String sql = dialect.forDeleteEntityById(tableInfo);
+        System.out.println(sql);
+    }
+
 
     @Test
     public void testrSelectLimitSql() {