mybatis-plus批次更新太慢該如何解決詳解

2023-03-05 14:02:53

最近使用mybatis-plus的 saveOrUpdateBath 和saveBath介面執行特別慢，資料量大時往往需要十幾分鍾，開啟紀錄檔檢視原來批次操作也是迴圈單條資料插入的，那有沒有批次更新的辦法呢？？

mybatis-plus 提供了一個自定義方法sql注入器DefaultSqlInjector我們可以通過繼DefaultSqlInjector來加入自定義的方法達到批次插入的效果。

import com.baomidou.mybatisplus.core.injector.AbstractMethod;
import com.baomidou.mybatisplus.core.injector.DefaultSqlInjector;
import org.springframework.stereotype.Component;
 
import java.util.List;
 
/**
 * @Description: 自定義方法SQL隱碼攻擊器
 * @Title: CustomizedSqlInjector
 * @Package com.highgo.edu.common.batchOperation
 * @Author:
 * @Copyright 
 * @CreateTime: 2022/11/3 16:21
 */
@Component
public class CustomizedSqlInjector  extends DefaultSqlInjector {
    /**
     * 如果只需增加方法，保留mybatis plus自帶方法，
     * 可以先獲取super.getMethodList()，再新增add
     */
    @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;
    }
 
}

同時我們需要繼承BaseMapper<T> 定義

 
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Param;
 
import java.util.List;
/**
 * @description:自定義介面覆蓋BaseMapper，解決mybatis-plus 批次操作慢的問題
 * @author:
 * @date: 2022/11/3 15:14
 * @param: null
 * @return:
 **/
public interface RootMapper<T> extends BaseMapper<T> {
    /**
     * @description:批次插入
     * @author:
     * @date: 2022/11/3 15:13
     * @param: [list]
     * @return: int
     **/
    int insertBatch(@Param("list") List<T> list);
    /**
     * @description:批次插入更新
     * @author:
     * @date: 2022/11/3 15:14
     * @param: [list]
     * @return: int
     **/
    int mysqlInsertOrUpdateBatch(@Param("list") List<T> list);
 
    int pgInsertOrUpdateBatch(@Param("list") List<T> list);
}

在需要使用批次更新插入的mapper上使用自定義的RootMapper

如下圖

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

下面我們來定義批次插入的方法：

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: 批次插入的方法
 * @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 = "<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;
        // 表包含主鍵處理邏輯,如果不包含主鍵當普通欄位處理
        if (StringUtils.isNotEmpty(tableInfo.getKeyProperty())) {
            if (tableInfo.getIdType() == IdType.AUTO) {
                /* 自增主鍵 */
                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();
                }
            }
        }
        // 第三個引數必須和RootMapper的自定義方法名一致
        return this.addInsertMappedStatement(mapperClass, modelClass, "insertBatch", sqlSource, keyGenerator, keyProperty, keyColumn);
    }
 
    /**
     * @description: 拼接欄位值
     * @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("<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();
    }
 
    /**
     * @description:拼接欄位
     * @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();
    }
}

繼續定義批次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: 批次插入更新
 * @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);
        // 第三個引數必須和RootMapper的自定義方法名一致
        return this.addInsertMappedStatement(mapperClass, modelClass, prepareInsertOrUpdateBathName(), sqlSource, new NoKeyGenerator(), null, null);
 
    }
 
    protected abstract SqlSource prepareSqlSource(TableInfo tableInfo, Class<?> modelClass);
    
    protected abstract String prepareInsertOrUpdateBathName();
 
}

繼承上面的抽象類----mysql版本（本版本未測試根據自己需求修改）

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: 批次插入更新
 * @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 = "<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();
    }
 
    /**
     * @description:準備屬性名
     * @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();
    }
}

繼承上面的抽象類----postgresql版本（已測試完成，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: 批次插入更新
 * @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 = "<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();
    }
 
    /**
     * @description:準備屬性名
     * @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();
    }
}

到此定義結束，下面開始使用

@Service
public class TNewExerciseServiceImpl extends ServiceImpl<TNewExerciseMapper, TNewExercise>
        implements TNewExerciseService {
    Logger logger = LoggerFactory.getLogger(getClass());
//引入mapper 
@Autowired
TScoreMapper scoreMapper;
//這樣就可以批次新增更新操作了
public void test(List<TScore> collect){
 scoreMapper.pgInsertOrUpdateBatch(collect);
}
 
}

但是如果collect資料量太大會出現異常
“Tried to send an out-of-range integer as a 2-byte value: 87923”
是因為pg對於sql語句的引數數量是有限制的，最大為32767。

看pg原始碼

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);
        }
    }

從原始碼中可以看到pgsql使用2個位元組的integer，故其取值範圍為[-32768, 32767]。

這意味著sql語句的引數數量，即行數*列數之積必須小於等於32767.

比如，總共有17個欄位，因為最大是32767，這樣最多允許32767/ 17 大約是1 927個，所以要分批操作，或有能力的童鞋可以自己修改pg的驅動呦

分批插入程式碼如下：

    /**
     * @description:
     * @author:
     * @date: 2022/11/4 14:57
     * @param: [list, fieldCount:列數]
     * @return: void
     **/
    public void detachSaveOrUpdate_score(List<TScore> list, int fieldCount) {
        int numberBatch = 32767; //每一次插入的最大數
        //每一次插入的最大行數 ， 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不能超過最大索引值
            }
            scoreMapper.pgInsertOrUpdateBatch(list.subList(v * i, end)); //插入資料庫
            logger.info("更新一次~~~{}-{}", v * i, end);
        }
    }

完成收工~~~

總結

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mybatis-plus批次更新太慢該如何解決詳解

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