问题:
Sharding-JDBC对订单表进行分库分表,16个库,每个库16张表。分片键订单id、用户id。分库规则,对分片键按1000取模再对16取模。分表规则,对分片键按1000取模再对256取模。配置文件如何写,以及ComplexKeysShardingAlgorithm实现代码?
回答:
针对订单表进行分库分表,每个库16张表,分片键为订单id和用户id,分库规则是对订单id按1000取模再对16取模,分表规则是对订单id按1000取模再对256取模。以下是配置文件和ComplexKeysShardingAlgorithm的实现代码示例: ### 配置文件(sharding-jdbc.yml):
datasource: names: ds0, ds1, ds2, ds3, ds4, ds5, ds6, ds7, ds8, ds9, ds10, ds11, ds12, ds13, ds14, ds15 # 配置16个数据源,具体配置信息省略 sharding: tables: order: actual-data-nodes: ds$->{0..15}.order_$->{0..15} database-strategy: complex: sharding-columns: order_id, user_id algorithm-class-name: com.example.algorithm.ComplexKeysShardingAlgorithm table-strategy: complex: sharding-columns: order_id, user_id algorithm-class-name: com.example.algorithm.ComplexKeysShardingAlgorithm
### ComplexKeysShardingAlgorithm实现代码:
package com.example.algorithm; import org.apache.shardingsphere.api.sharding.complex.ComplexKeysShardingAlgorithm; import org.apache.shardingsphere.api.sharding.complex.ComplexKeysShardingValue; import java.util.Collection; import java.util.LinkedHashSet; public class ComplexKeysShardingAlgorithm implements ComplexKeysShardingAlgorithm<Long> { @Override public Collection<String> doSharding(Collection<String> availableTargetNames, ComplexKeysShardingValue<Long> shardingValue) { Collection<String> result = new LinkedHashSet<>(); Long orderId = shardingValue.getValue("order_id"); Long userId = shardingValue.getValue("user_id"); if (orderId == null || userId == null) { throw new UnsupportedOperationException("Missing sharding key: order_id or user_id"); } long dbShard = (orderId % 1000) % 16; long tableShard = (orderId % 1000) % 256; for (String targetName : availableTargetNames) { if (targetName.endsWith(String.valueOf(dbShard)) && targetName.endsWith(String.valueOf(tableShard))) { result.add(targetName); } } return result; } }
在这个示例中,配置文件定义了对order表的分库分表规则,指定了ComplexKeysShardingAlgorithm作为算法类来处理分片逻辑。ComplexKeysShardingAlgorithm实现了ComplexKeysShardingAlgorithm接口,根据订单id和用户id来计算分库分表的逻辑。根据订单id计算出分库和分表的值,然后根据这些值来选择对应的数据源和表进行操作。 标签:取模,JDBC,16,sharding,分库,Sharding,ChatGPT,ComplexKeysShardingAlgorithm,id From: https://www.cnblogs.com/parkdifferent/p/18159784