mybatisplus 添加反引号

在 MybatisPlus 中添加反引号可以通过设置全局的 SQL 解析处理器实现，示例如下：

public class CustomSqlInjector extends DefaultSqlInjector {
    @Override
    public SqlNode inject(SqlNode sqlNode) {
        return new MybatisPlusResolveSqlInjector(sqlNode);
    }

    public static class MybatisPlusResolveSqlInjector extends AbstractWrapper {

        public MybatisPlusResolveSqlInjector(SqlNode sqlNode) {
            super(sqlNode);
        }

        @Override
        public void processWrapper(MappedStatement ms, Class<?> mapperClass, Method method) {
            SqlSource sqlSource = ms.getSqlSource();
            if (sqlSource instanceof DynamicSqlSource) {
                DynamicSqlSource dynamicSqlSource = (DynamicSqlSource) sqlSource;
                Field field = ReflectionUtils.findField(dynamicSqlSource.getClass(), "rootSqlNode");
                ReflectionUtils.makeAccessible(field);
                SqlNode rootSqlNode = (SqlNode) ReflectionUtils.getField(field, dynamicSqlSource);
                this.processDynamicSql(rootSqlNode);
            } else if (sqlSource instanceof RawSqlSource) {
                RawSqlSource rawSqlSource = (RawSqlSource) sqlSource;
                Field field = ReflectionUtils.findField(rawSqlSource.getClass(), "sqlSource");
                ReflectionUtils.makeAccessible(field);
                SqlNode rootSqlNode = (SqlNode) ReflectionUtils.getField(field, rawSqlSource);
                this.processDynamicSql(rootSqlNode);
            } else if (sqlSource instanceof ProviderSqlSource) {
                ProviderSqlSource providerSqlSource = (ProviderSqlSource) sqlSource;
                Field field = ReflectionUtils.findField(providerSqlSource.getClass(), "sqlProviderMethod");
                ReflectionUtils.makeAccessible(field);
                Method sqlProviderMethod = (Method) ReflectionUtils.getField(field, providerSqlSource);
                SqlNode rootSqlNode = this.parseProviderMethod(sqlProviderMethod, mapperClass);
                this.processDynamicSql(rootSqlNode);
            }
        }

        private void processDynamicSql(SqlNode sqlNode) {
            if (sqlNode instanceof TextSqlNode) {
                Field field = ReflectionUtils.findField(sqlNode.getClass(), "text");
                ReflectionUtils.makeAccessible(field);
                String text = (String) ReflectionUtils.getField(field, sqlNode);
                if (!text.contains("`")) {
                    ReflectionUtils.setField(field, sqlNode, "`" + text + "`");
                }
            } else if (sqlNode instanceof MixedSqlNode) {
                MixedSqlNode mixedSqlNode = (MixedSqlNode) sqlNode;
                List<SqlNode> contents = mixedSqlNode.getContents();
                for (int i = 0; i < contents.size(); i++) {
                    SqlNode item = contents.get(i);
                    if (item instanceof TextSqlNode) {
                        Field field = ReflectionUtils.findField(item.getClass(), "text");
                        ReflectionUtils.makeAccessible(field);
                        String text = (String) ReflectionUtils.getField(field, item);
                        if (!text.contains("`")) {
                            ReflectionUtils.setField(field, item, "`" + text + "`");
                        }
                    } else if (item instanceof IfSqlNode) {
                        Field field = ReflectionUtils.findField(item.getClass(), "contents");
                        ReflectionUtils.makeAccessible(field);
                        SqlNode contentsNode = ((SqlNode) ReflectionUtils.getField(field, item));
                        this.processDynamicSql(contentsNode);
                    }
                }
            } else if (sqlNode instanceof IfSqlNode) {
                Field field = ReflectionUtils.findField(sqlNode.getClass(), "contents");
                ReflectionUtils.makeAccessible(field);
                SqlNode contentsNode = ((SqlNode) ReflectionUtils.getField(field, sqlNode));
                this.processDynamicSql(contentsNode);
            } else if (sqlNode instanceof WhereSqlNode) {
                Field field = ReflectionUtils.findField(sqlNode.getClass(), "contents");
                ReflectionUtils.makeAccessible(field);
                SqlNode contentsNode = ((SqlNode) ReflectionUtils.getField(field, sqlNode));
                this.processDynamicSql(contentsNode);
            }
        }
    }
}

然后在 MybatisPlus 的配置类中将此处理器设置为全局的 SQL 解析处理器即可完成添加反引号的操作，示例如下：

@Configuration
public class MybatisPlusConfig {

    @Bean
    public MybatisPlusResolveSqlInjector mybatisPlusResolveSqlInjector() {
        return new MybatisPlusResolveSqlInjector();
    }

    @Bean
    public MybatisSqlSessionFactoryBean mybatisSqlSessionFactoryBean(@Autowired DataSource dataSource,
                                                                       @Autowired MybatisPlusResolveSqlInjector mybatisPlusResolveSqlInjector) {
        MybatisSqlSessionFactoryBean bean = new MybatisSqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        MybatisConfiguration configuration = new MybatisConfiguration();
        configuration.setMapUnderscoreToCamelCase(true);
        configuration.setCacheEnabled(false);
        GlobalConfig globalConfig = new GlobalConfig();
        globalConfig.setSqlInjector(mybatisPlusResolveSqlInjector);
        bean.setGlobalConfig(globalConfig);
        bean.setConfiguration(configuration);
        return bean;
    }
}