mybatis-plus批量更新太慢，如何解决？
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
*/
@Component
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 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
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
*/
@Repository
public 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 = "";
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 = "";
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 = "";
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
@Service
public class TNewExerciseServiceImpl extends ServiceImpl
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 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：
/**
* @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 < 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~~~