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1. 自定义BaseMapper
import com.baomidou.mybatisplus.core.mapper.BaseMapper; import
com.baomidou.mybatisplus.core.toolkit.Constants; import
org.apache.ibatis.annotations.Param; import java.util.List; /** *
根Mapper，给表Mapper继承用的，可以自定义通用方法 * {@link
com.baomidou.mybatisplus.core.mapper.BaseMapper} * {@link
com.baomidou.mybatisplus.extension.service.IService} * {@link
com.baomidou.mybatisplus.extension.service.impl.ServiceImpl} */ public
interface RootMapper<T> extends BaseMapper<T> { /** * 自定义批量插入 *
如果要自动填充，@Param(xx) xx参数名必须是 list/collection/array 3个的其中之一 */ int
insertBatch(@Param("list") List<T> list); /** * 自定义批量更新，条件为主键 *
如果要自动填充，@Param(xx) xx参数名必须是 list/collection/array 3个的其中之一 */ int
updateBatch(@Param("list") List<T> list); }
2. 批量插入方法实现
import com.baomidou.mybatisplus.core.injector.AbstractMethod; import
com.baomidou.mybatisplus.core.metadata.TableInfo; import
lombok.extern.slf4j.Slf4j; import
org.apache.ibatis.executor.keygen.NoKeyGenerator; import
org.apache.ibatis.mapping.MappedStatement; import
org.apache.ibatis.mapping.SqlSource; /** * 批量插入方法实现 */ @Slf4j public class
InsertBatchMethod extends AbstractMethod { /** * insert into user(id, name,
age) values (1, "a", 17), (2, "b", 18); <script> insert into user(id, name,
age) values <foreach collection="list" item="item" index="index" open="("
separator="),(" close=")"> #{item.id}, #{item.name}, #{item.age} </foreach>
</script> */ @Override public MappedStatement injectMappedStatement(Class<?>
mapperClass, Class<?> modelClass, TableInfo tableInfo) { final String sql =
"<script>insert into %s %s values %s</script>"; final String fieldSql =
prepareFieldSql(tableInfo); final String valueSql =
prepareValuesSql(tableInfo); final String sqlResult = String.format(sql,
tableInfo.getTableName(), fieldSql, valueSql); log.debug("sqlResult----->{}",
sqlResult); SqlSource sqlSource = languageDriver.createSqlSource(configuration,
sqlResult, modelClass); // 第三个参数必须和RootMapper的自定义方法名一致 return
this.addInsertMappedStatement(mapperClass, modelClass, "insertBatch",
sqlSource, new NoKeyGenerator(), null, null); } private String
prepareFieldSql(TableInfo tableInfo) { StringBuilder fieldSql = new
StringBuilder(); fieldSql.append(tableInfo.getKeyColumn()).append(",");
tableInfo.getFieldList().forEach(x -> {
fieldSql.append(x.getColumn()).append(","); });
fieldSql.delete(fieldSql.length() - 1, fieldSql.length()); fieldSql.insert(0,
"("); fieldSql.append(")"); return fieldSql.toString(); } private String
prepareValuesSql(TableInfo tableInfo) { final StringBuilder valueSql = new
StringBuilder(); valueSql.append("<foreach collection=\"list\" item=\"item\"
index=\"index\" open=\"(\" separator=\"),(\" close=\")\">");
valueSql.append("#{item.").append(tableInfo.getKeyProperty()).append("},");
tableInfo.getFieldList().forEach(x ->
valueSql.append("#{item.").append(x.getProperty()).append("},"));
valueSql.delete(valueSql.length() - 1, valueSql.length());
valueSql.append("</foreach>"); return valueSql.toString(); } }
3. 批量更新方法实现
import com.baomidou.mybatisplus.core.injector.AbstractMethod; import
com.baomidou.mybatisplus.core.metadata.TableInfo; import
lombok.extern.slf4j.Slf4j; import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.SqlSource; /** * 批量更新方法实现，条件为主键，选择性更新 */
@Slf4j public class UpdateBatchMethod extends AbstractMethod { /** * update
user set name = "a", age = 17 where id = 1; * update user set name = "b", age =
18 where id = 2; <script> <foreach collection="list" item="item" separator=";">
update user <set> <if test="item.name != null and item.name != ''"> name =
#{item.name,jdbcType=VARCHAR}, </if> <if test="item.age != null"> age =
#{item.age,jdbcType=INTEGER}, </if> </set> where id =
#{item.id,jdbcType=INTEGER} </foreach> </script> */ @Override public
MappedStatement injectMappedStatement(Class<?> mapperClass, Class<?>
modelClass, TableInfo tableInfo) { String sql = "<script>\n<foreach
collection=\"list\" item=\"item\" separator=\";\">\nupdate %s %s where %s=#{%s}
%s\n</foreach>\n</script>"; String additional = tableInfo.isWithVersion() ?
tableInfo.getVersionFieldInfo().getVersionOli("item", "item.") : "" +
tableInfo.getLogicDeleteSql(true, true); String setSql =
sqlSet(tableInfo.isWithLogicDelete(), false, tableInfo, false, "item",
"item."); String sqlResult = String.format(sql, tableInfo.getTableName(),
setSql, tableInfo.getKeyColumn(), "item." + tableInfo.getKeyProperty(),
additional); log.debug("sqlResult----->{}", sqlResult); SqlSource sqlSource =
languageDriver.createSqlSource(configuration, sqlResult, modelClass); //
第三个参数必须和RootMapper的自定义方法名一致 return this.addUpdateMappedStatement(mapperClass,
modelClass, "updateBatch", sqlSource); } }
4. 自定义方法SQL注入器
import com.baomidou.mybatisplus.core.injector.AbstractMethod; import
com.baomidou.mybatisplus.core.injector.DefaultSqlInjector; import
java.util.List; /** * 自定义方法SQL注入器 */ public class CustomizedSqlInjector extends
DefaultSqlInjector { /** * 如果只需增加方法，保留mybatis plus自带方法， *
可以先获取super.getMethodList()，再添加add */ @Override public List<AbstractMethod>
getMethodList(Class<?> mapperClass) { List<AbstractMethod> methodList =
super.getMethodList(mapperClass); methodList.add(new InsertBatchMethod());
methodList.add(new UpdateBatchMethod()); return methodList; } }
5. 配置SQL注入器使其生效
import cn.config.CustomizedSqlInjector; import
org.mybatis.spring.annotation.MapperScan; import
org.springframework.context.annotation.Bean; import
org.springframework.context.annotation.Configuration; @MapperScan(basePackages
= "cn.mapper") @Configuration public class MybatisPlusConfig { @Bean public
CustomizedSqlInjector customizedSqlInjector() { return new
CustomizedSqlInjector(); } }
备注：以下是当时所用的 Mybatis Plus 引用依赖版本，新版本可能需要结合Mybatis Plus最新官方文档进行调整。
<dependency> <groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId> <version>3.4.0</version>
</dependency>