MySQL Binlog Profile
- What is the binlog?
A binary log that records data on the occurrence of an SQL statement or potential changes and saved to disk in the form carried out.
- binlog role?
There are three main purposes:
Copy data (master-slave synchronization)
Mysql the Master-Slave protocol, let Slave data replication can be achieved by listening binlog, to achieve the purpose of data consistency
Data Recovery
Mysqlbinlog tool to recover data
- Incremental Backup
-
Binlog variable
-
log_bin (Binlog switch, used
show variables like 'log_bin';to view) - binlog_format (Binlog log format, use the
show variables like 'binlog_format';View)
There are three log format:
- ROW, only record-keeping details are modified, does not record SQL statements contextually relevant information. (Modification can clearly record the details of each row of data, context-sensitive information need not be recorded, procedure under certain circumstances it will not happen, function and call the trigger can not be accurately replicate the problem, in any case can be copy, and can speed up the efficiency replay logs from the library, to ensure the consistency of data from the library)
- STATEMENT, each modify SQL data will be recorded. (Only record the statement is executed details and context, to avoid changes in each line of the record, and in some cases modify records more than ROW binlog type can significantly reduce the amount of logging, saving IO, to improve performance. You can also use reduction in real-time, while the main can be different from the version, can be higher than the master server from the server version version)
- MIXED, 2 mixing the use thereof
-
-
Binlog management
- show master logs; see the list of all binlog log
- show master status; log number to view the last binlog name and position of the last event technology (position)
- Flush logs; refresh binlog, now began to produce a number of new binlog log file
- reset master; empty all the binlog log
-
Binlog related to SQL
show binlog events[in 'log_name'][from position][limit [offset,]row_count]
-
常用的Binlog event
- QUERY - 与数据无关的操作，begin、drop table、truncate table等等
- TABLE_MAP - 记录下一个操作所对应的表信息，存储了数据库名称和表名称
- XID - 标记事务提交
- WRITE_ROWS 插入数据，即insert操作
- UPDATE_ROWS 更新数据，即update操作
- DELETE_ROWS 删除数据，即delete操作
Event包含header和data两部分，header提供了event的创建时间，哪个服务器等信息，data部分提供的是针对该event的具体信息，如具体数据的修改。
Tip: binlog不会记录数据表的列名
在接下来的实现中，我们会将自己的系统包装成一个假的Mysql Slave，通过开源工具mysql-binlog-connector-java来实现监听binlog。
开源工具mysql-binlog-connector-java
-
工具源码：Github传送门
-
组件使用
1.加依赖
<!-- binlog 日志监听,解析开源工具类库 --> <dependency> <groupId>com.github.shyiko</groupId> <artifactId>mysql-binlog-connector-java</artifactId> <version>0.18.1</version> </dependency>2.创建一个测试接口
package com.sxzhongf.ad.service; import com.github.shyiko.mysql.binlog.BinaryLogClient; import com.github.shyiko.mysql.binlog.event.DeleteRowsEventData; import com.github.shyiko.mysql.binlog.event.EventData; import com.github.shyiko.mysql.binlog.event.UpdateRowsEventData; import com.github.shyiko.mysql.binlog.event.WriteRowsEventData; import java.io.IOException; /** * BinlogServiceTest for 测试Mysql binlog 监控 * {@code * Mysql8 连接提示 Client does not support authentication protocol requested by server; consider upgrading MySQL client 解决方法 * USE mysql; * ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password'; * FLUSH PRIVILEGES; * } * * @author <a href="mailto:[email protected]">Isaac.Zhang | 若初</a> */ public class BinlogServiceTest { /** * --------Update----------- * UpdateRowsEventData{tableId=90, includedColumnsBeforeUpdate={0, 1, 2, 3, 4, 5, 6, 7}, includedColumns={0, 1, 2, 3, 4, 5, 6, 7}, rows=[ * {before=[11, 10, Test Bin Log, 1, Tue Jun 25 08:00:00 CST 2019, Tue Jun 25 08:00:00 CST 2019, Tue Jun 25 08:00:00 CST 2019, Tue Jun 25 08:00:00 CST 2019], after=[11, 10, zhangpan test Binlog, 1, Tue Jun 25 08:00:00 CST 2019, Tue Jun 25 08:00:00 CST 2019, Tue Jun 25 08:00:00 CST 2019, Tue Jun 25 08:00:00 CST 2019]} * ]} * * --------Insert----------- * WriteRowsEventData{tableId=91, includedColumns={0, 1, 2, 3, 4, 5, 6, 7}, rows=[ * [10, 11, ad unit test binlog, 1, 0, 1236.7655, Thu Jun 27 08:00:00 CST 2019, Thu Jun 27 08:00:00 CST 2019] * ]} */ public static void main(String[] args) throws IOException { // //构造BinaryLogClient，填充mysql链接信息 BinaryLogClient client = new BinaryLogClient("127.0.0.1", 3306, "root", "12345678" ); //设置需要读取的Binlog的文件以及位置，否则，client会从"头"开始读取Binlog并监听 // client.setBinlogFilename("binlog.000035"); // client.setBinlogPosition(); //给客户端注册监听器，实现对Binlog的监听和解析 //event 就是监听到的Binlog变化信息，event包含header & data 两部分 client.registerEventListener(event -> { EventData data = event.getData(); if (data instanceof UpdateRowsEventData) { System.out.println("--------Update-----------"); System.out.println(data.toString()); } else if (data instanceof WriteRowsEventData) { System.out.println("--------Insert-----------"); System.out.println(data.toString()); } else if (data instanceof DeleteRowsEventData) { System.out.println("--------Delete-----------"); System.out.println(data.toString()); } }); client.connect(); } }运行：
八月 08, 2019 9:13:32 上午 com.github.shyiko.mysql.binlog.BinaryLogClient connect 信息: Connected to 127.0.0.1:3306 at binlog.000038/951 (sid:65535, cid:336) ...执行sql
update ad_user set user_status=1 where user_id=10;
我们需要知道的是，我们的目的是实现对Mysql数据表的变更实现监听，并解析成我们想要的格式，也就是我们的java对象。根据上面我们看到的监听结果，我们知道了返回信息的大概内容，既然我们已经学会了简单的使用BinaryLogClient 来监听binlog，接下来，我们需要定义一个监听器，来实现我们自己的业务内容。
因为我们只需要Event中的内容，那么我们也就只需要通过实现com.github.shyiko.mysql.binlog.BinaryLogClient.EventListener接口，来自定义一个监听器实现我们的业务即可。通过Event的内容，来判定是否需要处理当前event以及如何处理。
构造解析binlog的模版文件
我们监听binlog来构造增量数据的根本原因，是为了将我们的广告投放系统和广告检索系统 业务解耦，由于我们的检索系统中没有定义数据库以及数据表的相关，所以，我们通过定义一份模版文件，通过解析模版文件来得到我们需要的数据库和表信息，因为binlog的监听是不区分是哪个数据库和哪个数据表信息的，我们可以通过模版来指定我们想要监听的部分。
{
"database": "advertisement",
"tableList": [
{
"tableName": "ad_plan",
"level": 2,
"insert": [
{
"column": "plan_id"
},
{
"column": "user_id"
},
{
"column": "plan_status"
},
{
"column": "start_date"
},
{
"column": "end_date"
}
],
"update": [
{
"column": "plan_id"
},
{
"column": "user_id"
},
{
"column": "plan_status"
},
{
"column": "start_date"
},
{
"column": "end_date"
}
],
"delete": [
{
"column": "plan_id"
}
]
},
{
"tableName": "ad_unit",
"level": 3,
"insert": [
{
"column": "unit_id"
},
{
"column": "unit_status"
},
{
"column": "position_type"
},
{
"column": "plan_id"
}
],
"update": [
{
"column": "unit_id"
},
{
"column": "unit_status"
},
{
"column": "position_type"
},
{
"column": "plan_id"
}
],
"delete": [
{
"column": "unit_id"
}
]
},
{
"tableName": "ad_creative",
"level": 2,
"insert": [
{
"column": "creative_id"
},
{
"column": "type"
},
{
"column": "material_type"
},
{
"column": "height"
},
{
"column": "width"
},
{
"column": "audit_status"
},
{
"column": "url"
}
],
"update": [
{
"column": "creative_id"
},
{
"column": "type"
},
{
"column": "material_type"
},
{
"column": "height"
},
{
"column": "width"
},
{
"column": "audit_status"
},
{
"column": "url"
}
],
"delete": [
{
"column": "creative_id"
}
]
},
{
"tableName": "relationship_creative_unit",
"level": 3,
"insert": [
{
"column": "creative_id"
},
{
"column": "unit_id"
}
],
"update": [
],
"delete": [
{
"column": "creative_id"
},
{
"column": "unit_id"
}
]
},
{
"tableName": "ad_unit_district",
"level": 4,
"insert": [
{
"column": "unit_id"
},
{
"column": "province"
},
{
"column": "city"
}
],
"update": [
],
"delete": [
{
"column": "unit_id"
},
{
"column": "province"
},
{
"column": "city"
}
]
},
{
"tableName": "ad_unit_hobby",
"level": 4,
"insert": [
{
"column": "unit_id"
},
{
"column": "hobby_tag"
}
],
"update": [
],
"delete": [
{
"column": "unit_id"
},
{
"column": "hobby_tag"
}
]
},
{
"tableName": "ad_unit_keyword",
"level": 4,
"insert": [
{
"column": "unit_id"
},
{
"column": "keyword"
}
],
"update": [
],
"delete": [
{
"column": "unit_id"
},
{
"column": "keyword"
}
]
}
]
}上面的模版文件中，指定了一个数据库为advertisement，大家可以方便添加多个监听库。在数据库下面，我们监听了几个表的CUD操作以及每个操作所需要的字段信息。
-
实现模版 —> Java Entity
- 定义模版文件对应的实体
@Data @AllArgsConstructor @NoArgsConstructor public class BinlogTemplate { //单数据库对应 private String database; //多表 private List<JsonTable> tableList; }- 对应的json 中 table信息
/** * JsonTable for 用于表示template.json中对应的表信息 * * @author <a href="mailto:[email protected]">Isaac.Zhang | 若初</a> */ @Data @AllArgsConstructor @NoArgsConstructor public class JsonTable { private String tableName; private Integer level; private List<Column> insert; private List<Column> update; private List<Column> delete; @Data @AllArgsConstructor @NoArgsConstructor public static class Column { private String columnName; } }- 读取的对应表信息对象（最主要目的就是为了能将
字段索引映射到字段名称）
@Data @AllArgsConstructor @NoArgsConstructor public class TableTemplate { private String tableName; private String level; //操作类型 -> 多列 private Map<OperationTypeEnum, List<String>> opTypeFieldSetMap = new HashMap<>(); /** * Binlog日志中 字段索引 -> 字段名称 的一个转换映射 * 因为binlog中不会显示更新的列名是什么，它只会展示字段的索引，因此我们需要实现一次转换 */ private Map<Integer, String> posMap = new HashMap<>(); }- 解析模版文件到java对象
@Data public class ParseCustomTemplate { private String database; /** * key -> TableName * value -> {@link TableTemplate} */ private Map<String, TableTemplate> tableTemplateMap; public static ParseCustomTemplate parse(BinlogTemplate _template) { ParseCustomTemplate template = new ParseCustomTemplate(); template.setDatabase(_template.getDatabase()); for (JsonTable jsonTable : _template.getTableList()) { String name = jsonTable.getTableName(); Integer level = jsonTable.getLevel(); TableTemplate tableTemplate = new TableTemplate(); tableTemplate.setTableName(name); tableTemplate.setLevel(level.toString()); template.tableTemplateMap.put(name, tableTemplate); //遍历操作类型对应的列信息 Map<OperationTypeEnum, List<String>> operationTypeListMap = tableTemplate.getOpTypeFieldSetMap(); for (JsonTable.Column column : jsonTable.getInsert()) { getAndCreateIfNeed( OperationTypeEnum.ADD, operationTypeListMap, ArrayList::new ).add(column.getColumnName()); } for (JsonTable.Column column : jsonTable.getUpdate()) { getAndCreateIfNeed( OperationTypeEnum.UPDATE, operationTypeListMap, ArrayList::new ).add(column.getColumnName()); } for (JsonTable.Column column : jsonTable.getDelete()) { getAndCreateIfNeed( OperationTypeEnum.DELETE, operationTypeListMap, ArrayList::new ).add(column.getColumnName()); } } return template; } /** * 从Map中获取对象，如果不存在，创建一个 */ private static <T, R> R getAndCreateIfNeed(T key, Map<T, R> map, Supplier<R> factory) { return map.computeIfAbsent(key, k -> factory.get()); } }- 解析 字段索引 -> 字段名称 的一个转换映射
首先，我们来看一下binlog的具体日志信息：
--------Insert----------- WriteRowsEventData{tableId=91, includedColumns={0, 1, 2, 3, 4, 5, 6, 7}, rows=[ [10, 11, ad unit test binlog, 1, 0, 1236.7655, Thu Jun 27 08:00:00 CST 2019, Thu Jun 27 08:00:00 CST 2019] --------Update----------- UpdateRowsEventData{tableId=81, includedColumnsBeforeUpdate={0, 1, 2, 3, 4, 5}, includedColumns={0, 1, 2, 3, 4, 5}, rows=[ {before=[10, Isaac Zhang, 2D3ABB6F2434109A105170FB21D00453, 0, Fri Jun 21 15:07:53 CST 2019, Fri Jun 21 15:07:53 CST 2019], after=[10, Isaac Zhang, 2D3ABB6F2434109A105170FB21D00453, 1, Fri Jun 21 15:07:53 CST 2019, Fri Jun 21 15:07:53 CST 2019]}可以看到，在日志中
includedColumns只包含了{0, 1, 2, 3, 4, 5}位置信息，那么我们怎么能知道它具体代表的是哪个字段呢，接下来我们来实现这步映射关系，在实现之前，我们先来查询一下数据库中我们的表中字段所处的具体位置：sql> SELECT table_schema,table_name,column_name,ordinal_position FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = 'advertisement' AND TABLE_NAME='ad_user'
我们可以看到
ordinal_position对应的是1-6，可是上面监听到的binlog日志索引是0-5，所以我们就可以看出来之间的对应关系。我们开始编码实现，我们使用
JdbcTemplate进行查询数据库信息：@Slf4j @Component public class TemplateHolder { private ParseCustomTemplate template; private final JdbcTemplate jdbcTemplate; private String SQL_SCHEMA = "SELECT TABLE_SCHEMA,TABLE_NAME,COLUMN_NAME,ORDINAL_POSITION FROM information_schema.COLUMNS " + "WHERE TABLE_SCHEMA = ? AND TABLE_NAME = ?"; @Autowired public TemplateHolder(JdbcTemplate jdbcTemplate) { this.jdbcTemplate = jdbcTemplate; } /** * 需要在容器加载的时候，就载入数据信息 */ @PostConstruct private void init() { loadJSON("template.json"); } /** * 对外提供加载服务 */ public TableTemplate getTable(String tableName) { return template.getTableTemplateMap().get(tableName); } /** * 加载需要监听的binlog json文件 */ private void loadJSON(String path) { ClassLoader classLoader = Thread.currentThread().getContextClassLoader(); InputStream inputStream = classLoader.getResourceAsStream(path); try { BinlogTemplate binlogTemplate = JSON.parseObject( inputStream, Charset.defaultCharset(), BinlogTemplate.class ); this.template = ParseCustomTemplate.parse(binlogTemplate); loadMeta(); } catch (IOException ex) { log.error((ex.getMessage())); throw new RuntimeException("fail to parse json file"); } } /** * 加载元信息 * 使用表索引到列名称的映射关系 */ private void loadMeta() { for (Map.Entry<String, TableTemplate> entry : template.getTableTemplateMap().entrySet()) { TableTemplate table = entry.getValue(); List<String> updateFields = table.getOpTypeFieldSetMap().get( OperationTypeEnum.UPDATE ); List<String> insertFields = table.getOpTypeFieldSetMap().get( OperationTypeEnum.ADD ); List<String> deleteFields = table.getOpTypeFieldSetMap().get( OperationTypeEnum.DELETE ); jdbcTemplate.query(SQL_SCHEMA, new Object[]{ template.getDatabase(), table.getTableName() }, (rs, i) -> { int pos = rs.getInt("ORDINAL_POSITION"); String colName = rs.getString("COLUMN_NAME"); if ((null != updateFields && updateFields.contains(colName)) || (null != insertFields && insertFields.contains(colName)) || (null != deleteFields && deleteFields.contains(colName))) { table.getPosMap().put(pos - 1, colName); } return null; } ); } } }-
监听binlog实现
- 定义Event 解析所需要转换的java对象
@Data public class BinlogRowData { private TableTemplate tableTemplate; private EventType eventType; private List<Map<String, String>> before; private List<Map<String, String>> after; }- 定义binlog client
BinaryLogClient
/** * CustomBinlogClient for 自定义Binlog Client * * @author <a href="mailto:[email protected]">Isaac.Zhang | 若初</a> * @since 2019/6/27 */ @Slf4j @Component public class CustomBinlogClient { private BinaryLogClient client; private final BinlogConfig config; private final AggregationListener listener; @Autowired public CustomBinlogClient(BinlogConfig config, AggregationListener listener) { this.config = config; this.listener = listener; } public void connect() { new Thread(() -> { client = new BinaryLogClient( config.getHost(), config.getPort(), config.getUsername(), config.getPassword() ); if (!StringUtils.isEmpty(config.getBinlogName()) && !config.getPosition().equals(-1L)) { client.setBinlogFilename(config.getBinlogName()); client.setBinlogPosition(config.getPosition()); } try { log.info("connecting to mysql start..."); client.connect(); log.info("connecting to mysql done!"); } catch (IOException e) { e.printStackTrace(); } }).start(); } public void disconnect() { try { log.info("disconnect to mysql start..."); client.disconnect(); log.info("disconnect to mysql done!"); } catch (IOException e) { e.printStackTrace(); } } }- 使用client注册事件监听器
com.github.shyiko.mysql.binlog.BinaryLogClient.EventListener
/** * Ilistener for 为了后续扩展不同的实现 * * @author <a href="mailto:[email protected]">Isaac.Zhang | 若初</a> */ public interface Ilistener { void register(); void onEvent(BinlogRowData eventData); }- 监听Binlog, 收集mysql binlog datas
@Slf4j @Component public class AggregationListener implements BinaryLogClient.EventListener { private String dbName; private String tbName; private Map<String, Ilistener> listenerMap = new HashMap<>(); @Autowired private TemplateHolder templateHolder; private String genKey(String dbName, String tbName) { return dbName + ":" + tbName; } /** * 根据表实现注册信息 */ public void register(String dbName, String tbName, Ilistener listener) { log.info("register : {}-{}", dbName, tbName); this.listenerMap.put(genKey(dbName, tbName), listener); } @Override public void onEvent(Event event) { EventType type = event.getHeader().getEventType(); log.info("Event type: {}", type); //数据库增删改之前，肯定有一个table_map event 的binlog if (type == EventType.TABLE_MAP) { TableMapEventData data = event.getData(); this.tbName = data.getTable(); this.dbName = data.getDatabase(); return; } //EXT_UPDATE_ROWS 是Mysql 8以上的type if (type != EventType.EXT_UPDATE_ROWS && type != EventType.EXT_WRITE_ROWS && type != EventType.EXT_DELETE_ROWS ) { return; } // 检查表名和数据库名是否已经正确填充 if (StringUtils.isEmpty(dbName) || StringUtils.isEmpty(tbName)) { log.error("Meta data got error. tablename:{},database:{}", tbName, dbName); return; } //找出对应数据表敏感的监听器 String key = genKey(this.dbName, this.tbName); Ilistener ilistener = this.listenerMap.get(key); if (null == ilistener) { log.debug("skip {}", key); } log.info("trigger event:{}", type.name()); try { BinlogRowData rowData = convertEventData2BinlogRowData(event.getData()); if (null == rowData) { return; } rowData.setEventType(type); ilistener.onEvent(rowData); } catch (Exception e) { e.printStackTrace(); log.error(e.getMessage()); } finally { this.dbName = ""; this.tbName = ""; } } /** * 解析Binlog数据到Java实体对象的映射 * * @param data binlog * @return java 对象 */ private BinlogRowData convertEventData2BinlogRowData(EventData data) { TableTemplate tableTemplate = templateHolder.getTable(tbName); if (null == tableTemplate) { log.warn("table {} not found.", tbName); return null; } List<Map<String, String>> afterMapList = new ArrayList<>(); for (Serializable[] after : getAfterValues(data)) { Map<String, String> afterMap = new HashMap<>(); int columnLength = after.length; for (int i = 0; i < columnLength; ++i) { //取出当前位置对应的列名 String colName = tableTemplate.getPosMap().get(i); //如果没有，则说明不需要该列 if (null == colName) { log.debug("ignore position: {}", i); continue; } String colValue = after[i].toString(); afterMap.put(colName, colValue); } afterMapList.add(afterMap); } BinlogRowData binlogRowData = new BinlogRowData(); binlogRowData.setAfter(afterMapList); binlogRowData.setTableTemplate(tableTemplate); return binlogRowData; } /** * 获取不同事件的变更后数据 * Add & Delete变更前数据假定为空 */ private List<Serializable[]> getAfterValues(EventData eventData) { if (eventData instanceof WriteRowsEventData) { return ((WriteRowsEventData) eventData).getRows(); } if (eventData instanceof UpdateRowsEventData) { return ((UpdateRowsEventData) eventData).getRows() .stream() .map(Map.Entry::getValue) .collect(Collectors.toList() ); } if (eventData instanceof DeleteRowsEventData) { return ((DeleteRowsEventData) eventData).getRows(); } return Collections.emptyList(); } }- 解析binlog 数据对象
BinlogRowData,用于增量索引的后续处理
/** * MysqlRowData for 简化{@link BinlogRowData} 以方便实现增量索引的实现 * * @author <a href="mailto:[email protected]">Isaac.Zhang | 若初</a> */ @Data @AllArgsConstructor @NoArgsConstructor public class MysqlRowData { //实现多数据的时候，需要传递数据库名称 //private String database; private String tableName; private String level; private OperationTypeEnum operationTypeEnum; private List<Map<String, String>> fieldValueMap = new ArrayList<>(); }Binlog because we need to
EventTypeconvert our type of operationOperationTypeEnum, so weOperationTypeEnumadd a conversion method:public enum OperationTypeEnum { ... public static OperationTypeEnum convert(EventType type) { switch (type) { case EXT_WRITE_ROWS: return ADD; case EXT_UPDATE_ROWS: return UPDATE; case EXT_DELETE_ROWS: return DELETE; default: return OTHER; } } }We also need to define the java class name of each column of a table contained in the latter part of the CUD facilitate our operations data tables:
package com.sxzhongf.ad.mysql.constant; import java.util.HashMap; import java.util.Map; /** * Constant for 各个列名称的java类，方便我们后期对数据表的CUD操作 * * @author <a href="mailto:[email protected]">Isaac.Zhang | 若初</a> */ public class Constant { private static final String DATABASE_NAME = "advertisement"; public static class AD_PLAN_TABLE_INFO { public static final String TABLE_NAME = "ad_plan"; public static final String COLUMN_PLAN_ID = "plan_id"; public static final String COLUMN_USER_ID = "user_id"; public static final String COLUMN_PLAN_STATUS = "plan_status"; public static final String COLUMN_START_DATE = "start_date"; public static final String COLUMN_END_DATE = "end_date"; } public static class AD_CREATIVE_TABLE_INFO { public static final String TABLE_NAME = "ad_creative"; public static final String COLUMN_CREATIVE_ID = "creative_id"; public static final String COLUMN_TYPE = "type"; public static final String COLUMN_MATERIAL_TYPE = "material_type"; public static final String COLUMN_HEIGHT = "height"; public static final String COLUMN_WIDTH = "width"; public static final String COLUMN_AUDIT_STATUS = "audit_status"; public static final String COLUMN_URL = "url"; } public static class AD_UNIT_TABLE_INFO { public static final String TABLE_NAME = "ad_unit"; public static final String COLUMN_UNIT_ID = "unit_id"; public static final String COLUMN_UNIT_STATUS = "unit_status"; public static final String COLUNN_POSITION_TYPE = "position_type"; public static final String COLUNN_PLAN_ID = "plan_id"; } public static class RELATIONSHIP_CREATIVE_UNIT_TABLE_INFO { public static final String TABLE_NAME = "relationship_creative_unit"; public static final String COLUMN_CREATIVE_ID = "creative_id"; public static final String COLUMN_UNIT_ID = "unit_id"; } public static class AD_UNIT_DISTRICT_TABLE_INFO { public static final String TABLE_NAME = "ad_unit_district"; public static final String COLUMN_UNIT_ID = "unit_id"; public static final String COLUMN_PROVINCE = "province"; public static final String COLUMN_CITY = "city"; } public static class AD_UNIT_KEYWORD_TABLE_INFO { public static final String TABLE_NAME = "ad_unit_keyword"; public static final String COLUMN_UNIT_ID = "unit_id"; public static final String COLUMN_KEYWORD = "keyword"; } public static class AD_UNIT_HOBBY_TABLE_INFO { public static final String TABLE_NAME = "ad_unit_hobby"; public static final String COLUMN_UNIT_ID = "unit_id"; public static final String COLUMN_HOBBY_TAG = "hobby_tag"; } //key -> 表名 //value -> 数据库名 public static Map<String, String> table2db; static { table2db = new HashMap<>(); table2db.put(AD_PLAN_TABLE_INFO.TABLE_NAME, DATABASE_NAME); table2db.put(AD_CREATIVE_TABLE_INFO.TABLE_NAME, DATABASE_NAME); table2db.put(AD_UNIT_TABLE_INFO.TABLE_NAME, DATABASE_NAME); table2db.put(RELATIONSHIP_CREATIVE_UNIT_TABLE_INFO.TABLE_NAME, DATABASE_NAME); table2db.put(AD_UNIT_DISTRICT_TABLE_INFO.TABLE_NAME, DATABASE_NAME); table2db.put(AD_UNIT_HOBBY_TABLE_INFO.TABLE_NAME, DATABASE_NAME); table2db.put(AD_UNIT_KEYWORD_TABLE_INFO.TABLE_NAME, DATABASE_NAME); } }