mybatis-plus批量更新太慢该如何解决详解

mybatisplus 批量更新 mybatis-plus 批量更新 mybatis批量更新写法 2023-03-06 08:03:37 358人浏览八月长安

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摘要

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

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;
 

@Component
public class CustomizedSqlInjector  extends DefaultSqlInjector {
    
    @Override
    public List<AbstractMethod> getMethodList(Class<?> mapperClass) {
        List<AbstractMethod> 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<T> 定义

 
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Param;
 
import java.util.List;

public interface RootMapper<T> extends BaseMapper<T> {
    
    int insertBatch(@Param("list") List<T> list);
    
    int mysqlInsertOrUpdateBatch(@Param("list") List<T> list);
 
    int pgInsertOrUpdateBatch(@Param("list") List<T> 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;
 

@Repository
public interface TScoreMapper extends RootMapper<TScore> {
 
}

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;
 

public class InsertBatchMethod extends AbstractMethod {
    Logger logger = LoggerFactory.getLogger(getClass());
 
    @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);
        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) {
                
                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);
    }
 
    
    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();
    }
 
    
    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;
 

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;
 

public class MysqlInsertOrUpdateBath extends InsertOrUpdateBathAbstract {
 
    @Override
    protected SqlSource prepareSqlSource(TableInfo tableInfo, Class<?> modelClass) {
        final String sql = "<script>insert into %s %s values %s ON DUPLICATE KEY UPDATE %s</script>";
        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("<foreach collection=\"list\" item=\"item\" index=\"index\" open=\"(\" separator=\"),(\" close=\")\">");
        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("</foreach>");
        return valueSql.toString();
    }
 
    
    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;
 

public class PGInsertOrUpdateBath extends InsertOrUpdateBathAbstract {
    Logger logger = LoggerFactory.getLogger(getClass());
    @Override
    protected SqlSource prepareSqlSource(TableInfo tableInfo, Class<?> modelClass) {
        final String sql = "<script>insert into %s %s values %s on conflict (id)  do update set %s </script>";
        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("<foreach collection=\"list\" item=\"item\" index=\"index\" open=\"(\" separator=\"),(\" close=\")\">");
        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("</foreach>");
        return valueSql.toString();
    }
 
    
    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

@Service
public class TNewExerciseServiceImpl extends ServiceImpl<TNewExerciseMapper, TNewExercise>
        implements TNewExerciseService {
    Logger logger = LoggerFactory.getLogger(getClass());
//引入mapper 
@Autowired
TScoreMapper scoreMapper;
//这样就可以批量新增更新操作了
public void test(List<TScore> 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 <= 32767) {
            this.int2Buf[0] = (byte)(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：

    
    public void detachSaveOrUpdate_score(List<TScore> 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 < n; i++) {
            int end = v * (i + 1);
            if (end > 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~~~

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