TableStore：单行操作

2019独角兽企业重金招聘Python工程师标准>>>

TableStore数据准备：

首先需要添加TableStore的依赖

<dependency><groupId>com.aliyun.openservices</groupId><artifactId>tablestore</artifactId><version>4.10.2</version> </dependency>

运行项目时可能会出现SLF4J相关的红字提示：

该提示不影响使用，如果觉得不爽的话，可以添加下面依赖去除：

<dependency><groupId>org.slf4j</groupId><artifactId>slf4j-simple</artifactId><version>1.7.26</version> </dependency>

TableStore的主键含自增类型，该类型为Interger，但是值很大，不能通过这中自增主键查询数据，因此下面的SDK查询操作都是不允许有自增主键的。

另外。表中的数据操作，对Column或者说属性是有版本号这个概念的，该版本号以时间戳为准。当然，如果属性需要存储多个版本号的数据，在建表的时候要注意最大版本号这么一项，需要设置大于1。

1、根据主键查询数据

import com.alicloud.openservices.tablestore.SyncClient; import com.alicloud.openservices.tablestore.model.Column; import com.alicloud.openservices.tablestore.model.GetRowRequest; import com.alicloud.openservices.tablestore.model.GetRowResponse; import com.alicloud.openservices.tablestore.model.PrimaryKey; import com.alicloud.openservices.tablestore.model.PrimaryKeyBuilder; import com.alicloud.openservices.tablestore.model.PrimaryKeyValue; import com.alicloud.openservices.tablestore.model.Row; import com.alicloud.openservices.tablestore.model.SingleRowQueryCriteria;public class Query {public static void main(String[] args) {final String endPoint = "实例访问地址";final String accessKeyId = "accessKeyId";final String accessKeySecret = "accessKeySecret";// 实例名final String instanceName = "owlforest";SyncClient client = new SyncClient(endPoint, accessKeyId, accessKeySecret, instanceName);// 构造主键PrimaryKeyBuilder primaryKeyBuilder = PrimaryKeyBuilder.createPrimaryKeyBuilder();primaryKeyBuilder.addPrimaryKeyColumn("noteid", PrimaryKeyValue.fromLong(1));PrimaryKey primaryKey = primaryKeyBuilder.build();SingleRowQueryCriteria criteria = new SingleRowQueryCriteria("note", primaryKey);// 设置读取最新版本criteria.setMaxVersions(1);// 读取所有数据GetRowResponse getRowResponse = client.getRow(new GetRowRequest(criteria));Row row = getRowResponse.getRow();// 遍历所有列Column[] columns = row.getColumns();for (Column column : columns) {System.out.println("Name:" + column.getName() + " Value:" + column.getValue());}}}

如果只需要读取指定列，可以这样设置：

// 设置读取某些列 String[] a = { "author" }; criteria.addColumnsToGet(a); GetRowResponse getRowResponse2 = client.getRow(new GetRowRequest(criteria)); Row row2 = getRowResponse2.getRow(); Column[] columns2 = row2.getColumns(); for (Column column : columns2) {System.out.println("Name:" + column.getName() + " Value:" + column.getValue()); }

经测试，criteria.addColumnsToGet("author");这么设置运行也不会报错，不过仍然会读出所有属性。

2、根据主键查询数据-设置过滤器

可以表示的列与值的比较关系包括：EQUAL(=), NOT_EQUAL(!=), GREATER_THAN(>), GREATER_EQUAL(>=), LESS_THAN(<)以及LESS_EQUAL(<=)。

SyncClient client = new SyncClient(endPoint, accessKeyId, accessKeySecret, instanceName);// 构造主键 PrimaryKeyBuilder primaryKeyBuilder = PrimaryKeyBuilder.createPrimaryKeyBuilder(); primaryKeyBuilder.addPrimaryKeyColumn("noteid", PrimaryKeyValue.fromLong(1)); PrimaryKey primaryKey = primaryKeyBuilder.build();// 读一行 SingleRowQueryCriteria criteria = new SingleRowQueryCriteria("note", primaryKey); // 设置读取最新版本 criteria.setMaxVersions(1);//设置过滤器 SingleColumnValueFilter singleColumnValueFilter = new SingleColumnValueFilter( "author", CompareOperator.EQUAL, ColumnValue.fromString("I am zhangsan")); //如果不存在此列，也不返回 singleColumnValueFilter.setPassIfMissing(false); criteria.setFilter(singleColumnValueFilter);GetRowResponse getRowResponse = client.getRow(new GetRowRequest(criteria)); Row row = getRowResponse.getRow();if(row != null) {Column[] columns = row.getColumns();for(Column column : columns) { System.out.println("Name:" + column.getName() + " Value:" + column.getValue() + "\n");} }else {System.out.println("Row为空"); }

3、根据主键修改一行数据

修改前

SyncClient client = new SyncClient(endPoint, accessKeyId, accessKeySecret, instanceName);// 构造主键 PrimaryKeyBuilder primaryKeyBuilder = PrimaryKeyBuilder.createPrimaryKeyBuilder(); primaryKeyBuilder.addPrimaryKeyColumn("noteid", PrimaryKeyValue.fromLong(1)); PrimaryKey primaryKey = primaryKeyBuilder.build();RowUpdateChange rowUpdateChange = new RowUpdateChange("note", primaryKey); //修改author属性 rowUpdateChange.put(new Column("author", ColumnValue.fromString("我叫张三"))); //新增属性阅读量view rowUpdateChange.put(new Column("view", ColumnValue.fromLong(10))); //删除title属性 rowUpdateChange.deleteColumns("title"); // 删除某列的某一版本 //rowUpdateChange.deleteColumn(属性名, 版本号);UpdateRowResponse response = client.updateRow(new UpdateRowRequest(rowUpdateChange));

修改后

4、新增一行数据

SyncClient client = new SyncClient(endPoint, accessKeyId, accessKeySecret, instanceName);// 构造主键 PrimaryKeyBuilder primaryKeyBuilder = PrimaryKeyBuilder.createPrimaryKeyBuilder(); primaryKeyBuilder.addPrimaryKeyColumn("noteid", PrimaryKeyValue.fromLong(1)); PrimaryKey primaryKey = primaryKeyBuilder.build();RowPutChange rowPutChange = new RowPutChange("note", primaryKey); long ts = System.currentTimeMillis();rowPutChange.addColumn(new Column("year", ColumnValue.fromLong(2019), ts)); rowPutChange.addColumn(new Column("month", ColumnValue.fromLong(3), ts));rowPutChange.addColumn(new Column("day", ColumnValue.fromString("天"), ts + 1)); rowPutChange.addColumn(new Column("day", ColumnValue.fromString("日"), ts + 2));client.putRow(new PutRowRequest(rowPutChange));

note表当中原先就有一条noteid为1的数据，执行PutRow之后，发现原数据被新数据直接覆盖了。

5、期望原行不存在时写入

经测试：当主键1存在时，添加条件RowExistenceExpectation.EXPECT_NOT_EXIST，执行PutRow会出现异常Failed RetriedCount:0 [ErrorCode]:OTSConditionCheckFail, [Message]:Condition check failed.

如果构造的主键不存在于数据库，则可以正常插入。这个条件的使用场景比较让人费解，先记下，兴许后续会用上。

SyncClient client = new SyncClient(endPoint, accessKeyId, accessKeySecret, instanceName);// 构造主键 try {PrimaryKeyBuilder primaryKeyBuilder = PrimaryKeyBuilder.createPrimaryKeyBuilder();primaryKeyBuilder.addPrimaryKeyColumn("noteid", PrimaryKeyValue.fromLong(1));PrimaryKey primaryKey = primaryKeyBuilder.build();RowPutChange rowPutChange = new RowPutChange("note", primaryKey);rowPutChange.setCondition(new Condition(RowExistenceExpectation.EXPECT_NOT_EXIST));rowPutChange.addColumn(new Column("attr", ColumnValue.fromString("主键为1，看不到我"),System.currentTimeMillis()));client.putRow(new PutRowRequest(rowPutChange)); } catch (Exception e) {System.out.println(e.getMessage()); }

6、期望存在并某属性满足某条件时，覆盖写入行

同上，满足条件是覆盖该主键的数据，否则出错

SyncClient client = new SyncClient(endPoint, accessKeyId, accessKeySecret, instanceName); PrimaryKeyBuilder primaryKeyBuilder = PrimaryKeyBuilder.createPrimaryKeyBuilder(); primaryKeyBuilder.addPrimaryKeyColumn("noteid", PrimaryKeyValue.fromLong(2)); PrimaryKey primaryKey = primaryKeyBuilder.build(); RowPutChange rowPutChange = new RowPutChange("note", primaryKey);try {// 期望原行存在，且属性year=2019时插入Condition condition = new Condition(RowExistenceExpectation.EXPECT_EXIST);condition.setColumnCondition(new SingleColumnValueCondition("year", CompareOperator.EQUAL, ColumnValue.fromLong(2019)));rowPutChange.setCondition(condition);rowPutChange.addColumn(new Column("attr", ColumnValue.fromString("2019年")));client.putRow(new PutRowRequest(rowPutChange)); } catch (Exception e) {System.out.println(e.getMessage()); }

7、删除一行数据

SyncClient client = new SyncClient(endPoint, accessKeyId, accessKeySecret, instanceName);// 构造主键 PrimaryKeyBuilder primaryKeyBuilder = PrimaryKeyBuilder.createPrimaryKeyBuilder(); primaryKeyBuilder.addPrimaryKeyColumn("noteid", PrimaryKeyValue.fromLong(10)); PrimaryKey primaryKey = primaryKeyBuilder.build();RowDeleteChange rowDeleteChange = new RowDeleteChange("note", primaryKey); client.deleteRow(new DeleteRowRequest(rowDeleteChange));

8、根据条件删除数据

SyncClient client = new SyncClient(endPoint, accessKeyId, accessKeySecret, instanceName);// 构造主键 try {PrimaryKeyBuilder primaryKeyBuilder = PrimaryKeyBuilder.createPrimaryKeyBuilder();primaryKeyBuilder.addPrimaryKeyColumn("noteid", PrimaryKeyValue.fromLong(1));PrimaryKey primaryKey = primaryKeyBuilder.build();RowDeleteChange rowDeleteChange = new RowDeleteChange("note", primaryKey);Condition condition = new Condition(RowExistenceExpectation.EXPECT_EXIST);condition.setColumnCondition(new SingleColumnValueCondition("year",SingleColumnValueCondition.CompareOperator.EQUAL, ColumnValue.fromLong(2019)));rowDeleteChange.setCondition(condition);client.deleteRow(new DeleteRowRequest(rowDeleteChange)); } catch (Exception e) {System.out.println(e.getMessage()); }

转载于:https://my.oschina.net/u/4108765/blog/3059588

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