Mybatis-plus自定义SQL注入器查询@TableLogic逻辑删除后的数据详解

1  需求

Mybatis-plus使用@TableLogic注解进行逻辑删除数据后，在某些场景下，又需要查询该数据时，又不想写SQL。

2  解决方案

自定义Mybatis-plus的SQL注入器一劳永逸的解决该问题

3  方案：

3.1  方案1，继承 AbstractMethod拼接SQL语句

public class SelectIgnoreLogicDeleteByMap extends AbstractMethod {

@Override
   public MappedStatement injectMappedStatement(Class<?> mapperClass, Class<?> modelClass, TableInfo tableInfo) {

String sqlBase= "<script>SELECT ％s FROM ％s ％s\n</script>";
       String sqlScript = this.sqlWhereByMap(tableInfo);
       String sql = String.format(sqlBase, this.sqlSelectColumns(tableInfo, false), tableInfo.getTableName(), sqlScript);
       SqlSource sqlSource = this.languageDriver.createSqlSource(this.configuration, sql, Map.class);
       return this.addSelectMappedStatementForTable(mapperClass, "selectIgnoreLogicDeleteByMap", sqlSource, tableInfo);
   }

/**
    * 拼接where条件根据map参数
    *
    * @param table 表
    * @return sql
    */
   protected String sqlWhereByMap(TableInfo table) {
       String sqlScript;
       sqlScript = SqlScriptUtils.convertChoose("v == null", " ${k} IS NULL ", " ${k} = #{v} ");
       sqlScript = SqlScriptUtils.convertForeach(sqlScript, "cm", "k", "v", "AND");
       sqlScript = SqlScriptUtils.convertWhere(sqlScript);
       sqlScript = SqlScriptUtils.convertIf(sqlScript, String.format("％s != null and !％s", "cm", "cm.isEmpty"), true);
       return sqlScript;
   }
}

3.2. 方案2，继承 AbstractMethod拼接SQL语句

public class SelectIgnoreLogicDelete extends AbstractMethod {

@Override
   public MappedStatement injectMappedStatement(Class<?> mapperClass, Class<?> modelClass, TableInfo tableInfo) {

String sqlBase = "<script>％s SELECT ％s FROM ％s ％s ％s ％s\n</script>";

String sql = String.format(sqlBase, this.sqlFirst(), this.sqlSelectColumns(tableInfo, true), tableInfo.getTableName(), this.sqlWhereEntityWrapper(true, tableInfo), this.sqlOrderBy(tableInfo), this.sqlComment());
       SqlSource sqlSource = this.languageDriver.createSqlSource(this.configuration, sql, modelClass);
       return this.addSelectMappedStatementForTable(mapperClass, "selectIgnoreLogicDelete", sqlSource, tableInfo);
   }

/**
    * 拼接where条件
    *
    * @param newLine 新行
    * @param table   表
    * @return sql
    */
   protected String sqlWhereEntityWrapper(boolean newLine, TableInfo table) {
       String sqlScript = table.getAllSqlWhere(false, true, "ew.entity.");
       sqlScript = SqlScriptUtils.convertIf(sqlScript, String.format("％s != null", "ew.entity"), true);
       sqlScript = sqlScript + "\n";
       sqlScript = sqlScript + SqlScriptUtils.convertIf(String.format(SqlScriptUtils.convertIf(" AND", String.format("％s and ％s", "ew.nonEmptyOfEntity", "ew.nonEmptyOfNormal"), false) + " ${％s}", "ew.sqlSegment"), String.format("％s != null and ％s != '' and ％s", "ew.sqlSegment", "ew.sqlSegment", "ew.nonEmptyOfWhere"), true);
       sqlScript = SqlScriptUtils.convertWhere(sqlScript) + "\n";
       sqlScript = sqlScript + SqlScriptUtils.convertIf(String.format(" ${％s}", "ew.sqlSegment"), String.format("％s != null and ％s != '' and ％s", "ew.sqlSegment", "ew.sqlSegment", "ew.emptyOfWhere"), true);
       sqlScript = SqlScriptUtils.convertIf(sqlScript, String.format("％s != null", "ew"), true);
       return newLine ? "\n" + sqlScript : sqlScript;
   }

4.  自定义SQL注入器，注册上述自定义的方法

public class CustomSqlInjector extends DefaultSqlInjector {

@Override
   public List<AbstractMethod> getMethodList(Class<?> mapperClass, TableInfo tableInfo) {
       List<AbstractMethod> methodList = super.getMethodList(mapperClass, tableInfo);
       methodList.add(new SelectIgnoreLogicDeleteByMap());
       methodList.add(new SelectIgnoreLogicDelete());
       return methodList;
   }
}

5.  自定义基础mapper，声明注册的方法

public interface CustomBaseMapper<T> extends BaseMapper<T> {

/**
    * 根据map条件查询数据，并忽略逻辑删除
    *
    * @param columnMap 查询条件
    * @return 结果信息
    */
   List<T> selectIgnoreLogicDeleteByMap(@Param("cm") Map<String, Object> columnMap);

/**
    * 根据条件查询数据，并忽略逻辑删除
    *
    * @param queryWrapper 查询条件
    * @return 结果信息
    */
   List<T> selectIgnoreLogicDelete(@Param("ew") Wrapper<T> queryWrapper);
}

6. 使用声明的方法

6.1  业务mapper继承自定义的CustomBaseMapper

@Mapper
public interface UserMapper extends CustomBaseMapper<User> {
}

6.2 调用方法selectIgnoreLogicDelete

@Override
   public List<User> getIgnoreDeleteById(Long userId) {
       LambdaQueryWrapper<User> queryWrapper = new LambdaQueryWrapper<>();
       queryWrapper.eq(User::getId,userId);
       return this.baseMapper.selectIgnoreLogicDelete(queryWrapper);
   }

6.3 调用方法selectIgnoreLogicDeleteByMap

@Override
   public List<User> getIgnoreDeleteById(Long userId) {
Map<String, Object> columnMap = new HashMap<>(2);
       columnMap.put("id", userId);
       return this.baseMapper.selectIgnoreLogicDeleteByMap(columnMap);
   }

来源：https://blog.csdn.net/jinchunzhao123/article/details/127988188