最近使用mybatis-plus的 saveOrUpdateBath 和saveBath接口执行特别慢，数据量大时往往需要十几分钟，打开日志查看原来批量操作也是循环单条数据插入的，那有没有批量更新的办法呢？？
mybatis-plus 提供了一个自定义方法sql注入器DefaultSqlInjector我们可以通过继DefaultSqlInjector来加入自定义的方法达到批量插入的效果。
import com.baomidou.mybatisplus.core.injector.AbstractMethod;import com.baomidou.mybatisplus.core.injector.DefaultSqlInjector;import org.springframework.stereotype.Component;import java.util.List;/** * @Description: 自定义方法SQL注入器 * @Title: CustomizedSqlInjector * @Package com.highgo.edu.common.batchOperation * @Author: * @Copyright * @CreateTime: 2022/11/3 16:21 */@Componentpublic 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 getMethodList(Class mapperClass) { List methodList = super.getMethodList(mapperClass); methodList.add(new InsertBatchMethod()); // methodList.add(new UpdateBatchMethod()); methodList.add(new MysqlInsertOrUpdateBath()); methodList.add(new PGInsertOrUpdateBath()); return methodList; }}同时我们需要继承BaseMapper 定义
import com.baomidou.mybatisplus.core.mapper.BaseMapper;import org.apache.ibatis.annotations.Param;import java.util.List;/** * @description:自定义接口覆盖BaseMapper，解决mybatis-plus 批量操作慢的问题 * @author: * @date: 2022/11/3 15:14 * @param: null * @return: **/public interface RootMapper extends BaseMapper { /** * @description:批量插入 * @author: * @date: 2022/11/3 15:13 * @param: [list] * @return: int **/ int insertBatch(@Param("list") List list); /** * @description:批量插入更新 * @author: * @date: 2022/11/3 15:14 * @param: [list] * @return: int **/ int mysqlInsertOrUpdateBatch(@Param("list") List list); int pgInsertOrUpdateBatch(@Param("list") List list);}在需要使用批量更新插入的mapper上使用自定义的RootMapper
如下图
import com.XX.edu.common.batchOperation.RootMapper;import com.XX.edu.exam.model.TScore;import org.springframework.stereotype.Repository;/** * @Entity com.XX.edu.exam.model.TScore */@Repositorypublic interface TScoreMapper extends RootMapper {}下面我们来定义批量插入的方法：
package com.XX.edu.common.batchOperation;import com.baomidou.mybatisplus.annotation.IdType;import com.baomidou.mybatisplus.core.enums.SqlMethod;import com.baomidou.mybatisplus.core.injector.AbstractMethod;import com.baomidou.mybatisplus.core.metadata.TableInfo;import com.baomidou.mybatisplus.core.metadata.TableInfoHelper;import org.apache.commons.lang3.StringUtils;import org.apache.ibatis.executor.keygen.Jdbc3KeyGenerator;import org.apache.ibatis.executor.keygen.KeyGenerator;import org.apache.ibatis.executor.keygen.NoKeyGenerator;import org.apache.ibatis.mapping.MappedStatement;import org.apache.ibatis.mapping.SqlSource;import org.slf4j.Logger;import org.slf4j.LoggerFactory;/** * @Description: 批量插入的方法 * @Title: InsertBatchMethod * @Package com.XX.edu.common.batchOperation * @Author: * @CreateTime: 2022/11/3 15:16 */public class InsertBatchMethod extends AbstractMethod { Logger logger = LoggerFactory.getLogger(getClass()); @Override public MappedStatement injectMappedStatement(Class mapperClass, Class modelClass, TableInfo tableInfo) { final String sql = "insert into %s %s values %s"; final String fieldSql = prepareFieldSql(tableInfo); final String valueSql = prepareValuesSql(tableInfo); final String sqlResult = String.format(sql, tableInfo.getTableName(), fieldSql, valueSql); logger.debug("sqlResult----->{}", sqlResult); SqlSource sqlSource = languageDriver.createSqlSource(configuration, sqlResult, modelClass); KeyGenerator keyGenerator = new NoKeyGenerator(); SqlMethod sqlMethod = SqlMethod.INSERT_ONE; String keyProperty = null; String keyColumn = null; // 表包含主键处理逻辑,如果不包含主键当普通字段处理 if (StringUtils.isNotEmpty(tableInfo.getKeyProperty())) { if (tableInfo.getIdType() == IdType.AUTO) { /* 自增主键 */ keyGenerator = new Jdbc3KeyGenerator(); keyProperty = tableInfo.getKeyProperty(); keyColumn = tableInfo.getKeyColumn(); } else { if (null != tableInfo.getKeySequence()) { keyGenerator = TableInfoHelper.genKeyGenerator(sqlMethod.getMethod(),tableInfo, builderAssistant); keyProperty = tableInfo.getKeyProperty(); keyColumn = tableInfo.getKeyColumn(); } } } // 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, keyGenerator, keyProperty, keyColumn); } /** * @description: 拼接字段值 * @author: * @date: 2022/11/3 15:20 * @param: [tableInfo] * @return: java.lang.String **/ private String prepareValuesSql(TableInfo tableInfo) { final StringBuilder valueSql = new StringBuilder(); valueSql.append(""); //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(""); return valueSql.toString(); } /** * @description:拼接字段 * @author: * @date: 2022/11/3 15:20 * @param: [tableInfo] * @return: java.lang.String **/ 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(); }}继续定义批量插入更新的抽象方法
package com.XX.edu.common.batchOperation;import com.baomidou.mybatisplus.core.injector.AbstractMethod;import com.baomidou.mybatisplus.core.metadata.TableInfo;import org.apache.ibatis.executor.keygen.NoKeyGenerator;import org.apache.ibatis.mapping.MappedStatement;import org.apache.ibatis.mapping.SqlSource;/** * @Description: 批量插入更新 * @Title: InsertOrUpdateBath * @Package com.XX.edu.common.batchOperation * @Author: * @Copyright * @CreateTime: 2022/11/3 15:23 */public abstract class InsertOrUpdateBathAbstract extends AbstractMethod { @Override public MappedStatement injectMappedStatement(Class mapperClass, Class modelClass, TableInfo tableInfo) { final SqlSource sqlSource = prepareSqlSource(tableInfo, modelClass); // 第三个参数必须和RootMapper的自定义方法名一致 return this.addInsertMappedStatement(mapperClass, modelClass, prepareInsertOrUpdateBathName(), sqlSource, new NoKeyGenerator(), null, null); } protected abstract SqlSource prepareSqlSource(TableInfo tableInfo, Class modelClass); protected abstract String prepareInsertOrUpdateBathName();}继承上面的抽象类—-mysql版本（本版本未测试 根据自己需求修改）
package com.XX.edu.common.batchOperation;import com.baomidou.mybatisplus.core.metadata.TableInfo;import org.apache.ibatis.mapping.SqlSource;import org.springframework.util.StringUtils;/** * @Description: 批量插入更新 * @Title: InsertOrUpdateBath * @Package com.XX.edu.common.batchOperation * @Author: * @Copyright * @CreateTime: 2022/11/3 15:23 */public class MysqlInsertOrUpdateBath extends InsertOrUpdateBathAbstract { @Override protected SqlSource prepareSqlSource(TableInfo tableInfo, Class modelClass) { final String sql = "insert into %s %s values %s ON DUPLICATE KEY UPDATE %s"; final String tableName = tableInfo.getTableName(); final String filedSql = prepareFieldSql(tableInfo); final String modelValuesSql = prepareModelValuesSql(tableInfo); final String duplicateKeySql = prepareDuplicateKeySql(tableInfo); final String sqlResult = String.format(sql, tableName, filedSql, modelValuesSql, filedSql, duplicateKeySql); //String.format(sql, tableName, filedSql, modelValuesSql, duplicateKeySql); //System.out.println("savaorupdatesqlsql="+sqlResult); return languageDriver.createSqlSource(configuration, sqlResult, modelClass); } @Override protected String prepareInsertOrUpdateBathName() { return "mysqlInsertOrUpdateBath"; } String prepareDuplicateKeySql(TableInfo tableInfo) { final StringBuilder duplicateKeySql = new StringBuilder(); if (!StringUtils.isEmpty(tableInfo.getKeyColumn())) { duplicateKeySql.append(tableInfo.getKeyColumn()).append("=values(").append(tableInfo.getKeyColumn()).append("),"); } tableInfo.getFieldList().forEach(x -> { duplicateKeySql.append(x.getColumn()) .append("=values(") .append(x.getColumn()) .append("),"); }); duplicateKeySql.delete(duplicateKeySql.length() - 1, duplicateKeySql.length()); return duplicateKeySql.toString(); } String prepareModelValuesSql(TableInfo tableInfo) { final StringBuilder valueSql = new StringBuilder(); valueSql.append(""); if (!StringUtils.isEmpty(tableInfo.getKeyProperty())) { 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(""); return valueSql.toString(); } /** * @description:准备属性名 * @author: * @date: 2022/11/3 15:25 * @param: [tableInfo] * @return: java.lang.String **/ 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(); }}继承上面的抽象类—-postgresql版本（已测试完成，其中id使用序列自增）
package com.XX.edu.common.batchOperation;import com.baomidou.mybatisplus.core.metadata.TableInfo;import org.apache.ibatis.mapping.SqlSource;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.util.StringUtils;/** * @Description: 批量插入更新 * @Title: InsertOrUpdateBath * @Package com.XX.edu.common.batchOperation * @Author: * @Copyright * @CreateTime: 2022/11/3 15:23 */public class PGInsertOrUpdateBath extends InsertOrUpdateBathAbstract { Logger logger = LoggerFactory.getLogger(getClass()); @Override protected SqlSource prepareSqlSource(TableInfo tableInfo, Class modelClass) { final String sql = "insert into %s %s values %s on conflict (id) do update set %s "; final String tableName = tableInfo.getTableName(); final String filedSql = prepareFieldSql(tableInfo); final String modelValuesSql = prepareModelValuesSql(tableInfo); final String duplicateKeySql = prepareDuplicateKeySql(tableInfo); final String sqlResult = String.format(sql, tableName, filedSql, modelValuesSql, duplicateKeySql); logger.info("sql=={}",sqlResult); return languageDriver.createSqlSource(configuration, sqlResult, modelClass); } @Override protected String prepareInsertOrUpdateBathName() { return "pgInsertOrUpdateBatch"; } private String prepareDuplicateKeySql(TableInfo tableInfo) { final StringBuilder duplicateKeySql = new StringBuilder(); if (!StringUtils.isEmpty(tableInfo.getKeyColumn())) { duplicateKeySql.append(tableInfo.getKeyColumn()).append("=excluded.").append(tableInfo.getKeyColumn()).append(","); } tableInfo.getFieldList().forEach(x -> { duplicateKeySql.append(x.getColumn()) .append("=excluded.") .append(x.getColumn()) .append(","); }); duplicateKeySql.delete(duplicateKeySql.length() - 1, duplicateKeySql.length()); return duplicateKeySql.toString(); } private String prepareModelValuesSql(TableInfo tableInfo) { final StringBuilder valueSql = new StringBuilder(); valueSql.append(""); if (!StringUtils.isEmpty(tableInfo.getKeyProperty())) { 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(""); return valueSql.toString(); } /** * @description:准备属性名 * @author: * @date: 2022/11/3 15:25 * @param: [tableInfo] * @return: java.lang.String **/ private String prepareFieldSql(TableInfo tableInfo) { StringBuilder fieldSql = new StringBuilder(); if (!StringUtils.isEmpty(tableInfo.getKeyProperty())) { 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(); }}到此定义结束，下面开始使用
@Servicepublic class TNewExerciseServiceImpl extends ServiceImpl implements TNewExerciseService { Logger logger = LoggerFactory.getLogger(getClass());//引入mapper @AutowiredTScoreMapper scoreMapper;//这样就可以批量新增更新操作了public void test(List collect){ scoreMapper.pgInsertOrUpdateBatch(collect);}}但是如果collect数据量太大会出现异常
“Tried to send an out-of-range integer as a 2-byte value: 87923”
是因为pg对于sql语句的参数数量是有限制的，最大为32767。
看pg源码
public void sendInteger2(int val) throws IOException { if (val >= -32768 && val >> 8); this.int2Buf[1] = (byte)val; this.pgOutput.write(this.int2Buf); } else { throw new IOException("Tried to send an out-of-range integer as a 2-byte value: " + val); } }从源代码中可以看到pgsql使用2个字节的integer，故其取值范围为[-32768, 32767]。
这意味着sql语句的参数数量，即行数*列数之积必须小于等于32767.
比如，总共有17个字段，因为最大是32767，这样最多允许32767/ 17 大约是1 927个，所以要分批操作，或有能力的童鞋可以自己修改pg的驱动呦
分批插入代码如下：
/** * @description: * @author: * @date: 2022/11/4 14:57 * @param: [list, fieldCount:列数] * @return: void **/ public void detachSaveOrUpdate_score(List list, int fieldCount) { int numberBatch = 32767; //每一次插入的最大数 //每一次插入的最大行数 ， 向下取整 int v = ((Double) Math.floor(numberBatch / (fieldCount * 1.0))).intValue(); double number = list.size() * 1.0 / v; int n = ((Double) Math.ceil(number)).intValue(); //向上取整 for (int i = 0; i list.size()) { end = list.size(); //如果end不能超过最大索引值 } scoreMapper.pgInsertOrUpdateBatch(list.subList(v * i, end)); //插入数据库 logger.info("更新一次~~~{}-{}", v * i, end); } }完成收工~~~