mybatisPlus版本3.4.0
本文主要是对MybatisPlus的更新方法进行扩展，对set语句的非空校验进行自定义判断，提供了两个方法模板
/** * 根据主键更新字段，null也会更新 * @param entity * @author zhangyong * @date 2025/3/29 * @return int */ int updateIgnoreNullById(@Param("et") T entity); /** * 根据条件更新实体，null也会更新 * @author zhangyong * @date 2025/3/29 * @param entity: * @param updateWrapper: * @return int */ int updateIgnoreNull(@Param("et") T entity, @Param("ew") Wrapper<T> updateWrapper);MybatisPlus扩展接口需要四个步骤，第五步为使用
1、定义方法扩展
这部分必须实现injectMappedStatement接口，接口的内容可以参考com.baomidou.mybatisplus.core.injector.methods包和com.baomidou.mybatisplus.extension.injector.methods.AlwaysUpdateSomeColumnById接口的写法。
主要的拼接setsql的方法有两个,可以参考里面的实现来实现我们自己的逻辑，没必要自己造轮子。
a: AbstractMethod.filterTableFieldInfo
b.AbstractMethod.sqlSet
其中调用的TableFieldInfo.convertIf接口非常重要，是用来生成set字段外的if条件的，可以按需求调整。如：
<if test="accountId != null"> ac.account_id = #{accountId}, </if>代码中需要注意
return this.addUpdateMappedStatement(mapperClass, modelClass, "updateIgnoreNull", sqlSource);的updateIgnoreNull需要和Mapper里的方法名一样（重要）
a:根据自定义Wrapper条件更新数据,int updateIgnoreNullById(@Param("et") T entity);
package com.hk.abpms.data.api.config.method; import com.baomidou.mybatisplus.annotation.FieldStrategy; import com.baomidou.mybatisplus.core.enums.SqlMethod; import com.baomidou.mybatisplus.core.injector.AbstractMethod; import com.baomidou.mybatisplus.core.metadata.TableFieldInfo; import com.baomidou.mybatisplus.core.metadata.TableInfo; import com.baomidou.mybatisplus.core.toolkit.StringUtils; import com.baomidou.mybatisplus.core.toolkit.sql.SqlScriptUtils; import org.apache.ibatis.mapping.MappedStatement; import org.apache.ibatis.mapping.SqlSource; import java.util.function.Predicate; /** * 根据自定义Wrapper条件更新数据 * * @author zhangyong * @Date 2025/3/28 */ public class UpdateIgnoreNull extends AbstractMethod { private Predicate<TableFieldInfo> predicate; public UpdateIgnoreNull() { } @Override public MappedStatement injectMappedStatement(Class<?> mapperClass, Class<?> modelClass, TableInfo tableInfo) { SqlMethod sqlMethod = SqlMethod.UPDATE; if(tableInfo.getTableName().equals("cfg_api")){ System.out.println(tableInfo.getFieldList()); } String sqlSet = this.filterTableFieldInfo(tableInfo.getFieldList(), this.getPredicate(), (i) -> { //以下代码来自AbstractMethod.sqlSet String newPrefix = "et."; String sqlSet2 = i.getColumn() + "="; if (StringUtils.isNotBlank(i.getUpdate())) { sqlSet2 = sqlSet2 + String.format(i.getUpdate(), i.getColumn()); } else { sqlSet2 = sqlSet2 + SqlScriptUtils.safeParam(newPrefix + i.getEl()); } sqlSet2 = sqlSet2 + ","; return i.isWithUpdateFill() ? sqlSet2 : this.convertIf2(i,sqlSet2, this.convertIfProperty2(newPrefix, i.getProperty()), i.getUpdateStrategy()); }, "\n"); sqlSet = SqlScriptUtils.convertSet(sqlSet); String sql = String.format(sqlMethod.getSql(), tableInfo.getTableName(), sqlSet, this.sqlWhereEntityWrapper(true, tableInfo), this.sqlComment()); SqlSource sqlSource = this.languageDriver.createSqlSource(this.configuration, sql, modelClass); return this.addUpdateMappedStatement(mapperClass, modelClass, "updateIgnoreNull", sqlSource); } private String convertIf2(TableFieldInfo tableFieldInfo,final String sqlScript, final String property, final FieldStrategy fieldStrategy) { //判断Entity上的注解 if (fieldStrategy == FieldStrategy.NEVER) { //字段标记为用不更新的 不需要set语句。@TableField(updateStrategy = FieldStrategy.NEVER) return null; } else if (!tableFieldInfo.isPrimitive() && fieldStrategy != FieldStrategy.IGNORED) { //如果字段没有FieldStrategy.IGNORED注解（建议不要加这个注解，加了注解所有涉及这个Entity的保存该字段为null都会更新） if(tableFieldInfo.isWithInsertFill()){ //判断Entity字段是否配置了 @TableField(fill = FieldFill.INSERT)注解，理论上有这个注解的不需要修改，比如createBy等字段，所以此处set外拼接了if为空判断 return fieldStrategy == FieldStrategy.NOT_EMPTY && tableFieldInfo.isCharSequence() ? SqlScriptUtils.convertIf(sqlScript, String.format("%s != null and %s != ''", property, property), false) : SqlScriptUtils.convertIf(sqlScript, String.format("%s != null", property), false); }else{ //不添加if为空判断，null也会更新 return sqlScript; } } else { //不添加if为空判断，null也会更新 return sqlScript; } } private String convertIfProperty2(String prefix, String property) { return StringUtils.isNotBlank(prefix) ? prefix.substring(0, prefix.length() - 1) + "['" + property + "']" : property; } private Predicate<TableFieldInfo> getPredicate() { Predicate<TableFieldInfo> noLogic = (t) -> { return !t.isLogicDelete(); }; return this.predicate != null ? noLogic.and(this.predicate) : noLogic; } }B:根据ID更新数据int updateIgnoreNull(@Param("et") T entity, @Param("ew") Wrapper<T> updateWrapper);
package com.hk.abpms.data.api.config.method; import com.baomidou.mybatisplus.annotation.FieldStrategy; import com.baomidou.mybatisplus.core.enums.SqlMethod; import com.baomidou.mybatisplus.core.injector.AbstractMethod; import com.baomidou.mybatisplus.core.metadata.TableFieldInfo; import com.baomidou.mybatisplus.core.metadata.TableInfo; import com.baomidou.mybatisplus.core.toolkit.StringUtils; import com.baomidou.mybatisplus.core.toolkit.sql.SqlScriptUtils; import org.apache.ibatis.mapping.MappedStatement; import org.apache.ibatis.mapping.SqlSource; import java.util.Objects; import java.util.function.Predicate; import java.util.stream.Collectors; /** * 根据ID更新数据 * * @author zhangyong * @Date 2025/3/28 */ public class UpdateIgnoreNullById extends AbstractMethod { public UpdateIgnoreNullById() { } @Override public MappedStatement injectMappedStatement(Class<?> mapperClass, Class<?> modelClass, TableInfo tableInfo) { SqlMethod sqlMethod = SqlMethod.UPDATE_BY_ID; if(tableInfo.getTableName().equals("cfg_api")){ System.out.println(tableInfo.getFieldList()); } String additional = this.optlockVersion(tableInfo) + tableInfo.getLogicDeleteSql(true, true); String sql = String.format(sqlMethod.getSql(), tableInfo.getTableName(), this.sqlSet2(tableInfo.isWithLogicDelete(), false, tableInfo, false, "et", "et."), tableInfo.getKeyColumn(), "et." + tableInfo.getKeyProperty(), additional); SqlSource sqlSource = this.languageDriver.createSqlSource(this.configuration, sql, modelClass); return this.addUpdateMappedStatement(mapperClass, modelClass, "updateIgnoreNullById", sqlSource); } public String getAllSqlSet2( TableInfo table,boolean ignoreLogicDelFiled, final String prefix) { String newPrefix = prefix == null ? "" : prefix; return (String)table.getFieldList().stream().filter((i) -> { if (!ignoreLogicDelFiled) { return true; } else { return !table.isWithLogicDelete() || !i.isLogicDelete(); } }).map((i) -> { String sqlSet2 = i.getColumn() + "="; if (StringUtils.isNotBlank(i.getUpdate())) { sqlSet2 = sqlSet2 + String.format(i.getUpdate(), i.getColumn()); } else { sqlSet2 = sqlSet2 + SqlScriptUtils.safeParam(newPrefix + i.getEl()); } sqlSet2 = sqlSet2 + ","; return i.isWithUpdateFill() ? sqlSet2 : this.convertIf2(i,sqlSet2, this.convertIfProperty2(newPrefix, i.getProperty()), i.getUpdateStrategy()); }).filter(Objects::nonNull).collect(Collectors.joining("\n")); } protected String sqlSet2(boolean logic, boolean ew, TableInfo table, boolean judgeAliasNull, final String alias, final String prefix) { String sqlScript = this.getAllSqlSet2(table,logic, prefix); if (judgeAliasNull) { sqlScript = SqlScriptUtils.convertIf(sqlScript, String.format("%s != null", alias), true); } if (ew) { sqlScript = sqlScript + "\n"; sqlScript = sqlScript + SqlScriptUtils.convertIf(SqlScriptUtils.unSafeParam("ew.sqlSet"), String.format("%s != null and %s != null", "ew", "ew.sqlSet"), false); } sqlScript = SqlScriptUtils.convertSet(sqlScript); return sqlScript; } private String convertIf2(TableFieldInfo tableFieldInfo,final String sqlScript, final String property, final FieldStrategy fieldStrategy) { if (fieldStrategy == FieldStrategy.NEVER) { return null; } else if (!tableFieldInfo.isPrimitive() && fieldStrategy != FieldStrategy.IGNORED) { if(tableFieldInfo.isWithInsertFill()){ return fieldStrategy == FieldStrategy.NOT_EMPTY && tableFieldInfo.isCharSequence() ? SqlScriptUtils.convertIf(sqlScript, String.format("%s != null and %s != ''", property, property), false) : SqlScriptUtils.convertIf(sqlScript, String.format("%s != null", property), false); }else{ return sqlScript; } } else { return sqlScript; } } private String convertIfProperty2(String prefix, String property) { return StringUtils.isNotBlank(prefix) ? prefix.substring(0, prefix.length() - 1) + "['" + property + "']" : property; } }2、将方法加入MybatisPlus进行管理
package com.hk.abpms.data.api.config; import com.baomidou.mybatisplus.core.injector.AbstractMethod; import com.baomidou.mybatisplus.core.injector.DefaultSqlInjector; import com.baomidou.mybatisplus.extension.injector.methods.AlwaysUpdateSomeColumnById; import com.hk.abpms.data.api.config.method.UpdateIgnoreNull; import com.hk.abpms.data.api.config.method.UpdateIgnoreNullById; import java.util.List; /** * sql方法注入 * * @author zhangyong * @Date 2025/3/27 */ public class MybatisSqlInjector extends DefaultSqlInjector { @Override public List<AbstractMethod> getMethodList(Class<?> mapperClass) { List<AbstractMethod> methodList = super.getMethodList(mapperClass); // 添加自定义的更新方法，AlwaysUpdateSomeColumnById 会更新所有字段，包括空字段 methodList.add(new UpdateIgnoreNullById()); methodList.add(new UpdateIgnoreNull()); return methodList; } }3、将Injector加入springBean管理
package com.hk.abpms.data.api.config; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; /** * MybatisPlus的额外配置类 * * @author zhangyong * @Date 2025/3/28 */ @Configuration public class MyBatisPlusConfig { @Bean public MybatisSqlInjector customSqlInjector() { return new MybatisSqlInjector(); } }4、在BaseMapper中定义与第一步同名的方法
注意参数@Param("et")名字要和第一步的名称对应
package com.hk.abpms.data.api.config; import com.baomidou.mybatisplus.core.conditions.Wrapper; import com.baomidou.mybatisplus.core.mapper.BaseMapper; import org.apache.ibatis.annotations.Param; /** * 基础mapper * * @author zhangyong * @Date 2025/3/28 */ public interface BaseCommonMapper<T> extends BaseMapper<T> { /** * 根据主键更新字段，null也会更新 * @param entity * @author zhangyong * @date 2025/3/29 * @return int */ int updateIgnoreNullById(@Param("et") T entity); /** * 根据条件更新实体，null也会更新 * @author zhangyong * @date 2025/3/29 * @param entity: * @param updateWrapper: * @return int */ int updateIgnoreNull(@Param("et") T entity, @Param("ew") Wrapper<T> updateWrapper); }5、业务Mapper继承公共的BaseCommonMapper后就可正常使用里面的方法
最后：如果自己new了SqlSessionFactory需要将
MybatisSqlInjector手动设置进去
@Bean @ConditionalOnMissingBean(SqlSessionFactory.class) public SqlSessionFactory sqlSessionFactory(DataSource dataSource, MybatisPlusInterceptor interceptor, GlobalConfig globalConfig) throws Exception { MybatisSqlSessionFactoryBean bean = new MybatisSqlSessionFactoryBean(); bean.setDataSource(dataSource); bean.setPlugins(interceptor); bean.setMapperLocations(new PathMatchingResourcePatternResolver() .getResources("classpath*:mapping/**/*.xml")); bean.setGlobalConfig(globalConfig); return bean.getObject(); } /** * GlobalConfig必须设置自定义SqlInjector，否则BaseCommonMapper的自定义方法（updateNullFieldById/updateNullField） * 不会被注入，调用时抛BindingException: Invalid bound statement (not found) */ @Bean public GlobalConfig globalConfig(MybatisSqlInjector mybatisSqlInjector) { GlobalConfig config = new GlobalConfig(); config.setSqlInjector(mybatisSqlInjector); config.setMetaObjectHandler(new DefaultDBFieldHandler()); return config; }欢迎各位大佬留言。
