具有范围边界查询的Cassandra BoundStatement-Java 学习之路

我正在使用PreparedStatement和boundStatment来执行一些Cassandra查询 . 我正在尝试执行范围查询 . 这是我要创建的查询：

getAllRecordsOnIndexRange = getSession.prepare(QueryBuilder.select(documentId, documentName, documentIndex)
          .from(tableName)               
          .where(QueryBuilder.eq(documentId,QueryBuilder.bindMarker()))
          .and(QueryBuilder.gte(documentIndex, QueryBuilder.bindMarker()))
          .and(QueryBuilder.lte(documentIndex, QueryBuilder.bindMarker())));

'documentId' 是分区键， 'documentIndex' 是群集键 . 我想对列documentIndex进行范围查询，如"get me all records with given documentId and documentIndex >= 3 and documentIndex <= 10"

当我想运行查询时，我打电话

public Statement buildGetAllRecordsOnIndexRange(int documentId, String documentName, int startDocumentIndex, int endDocumentIndex)
{
    BoundStatement boundStatement = getAllRecordsOnIndexRange
            .bind()
            .setString(DOCUMENT_ID, documentId)
            //how to set start and end documentIndex
    databaseManager.applyReadStatementsConfiguration(boundStatement);
    return boundStatement;
}

如何为上述查询设置startDocumentIndex和endDocumentIndex？

1 回答

我建议使用named bind markers而不是未命名 - 读取使用它们的代码要容易得多 . 因此，在您的情况下，代码将如下所示：

PreparedStatement pStatement = session.prepare(QueryBuilder.select(documentId, documentName, documentIndex)
      .from(tableName)               
      .where(QueryBuilder.eq(documentId,QueryBuilder.bindMarker("documentId")))
      .and(QueryBuilder.gte(documentIndex, QueryBuilder.bindMarker("documentIndexStart")))
      .and(QueryBuilder.lte(documentIndex, QueryBuilder.bindMarker("documentIndexEnd"))));

然后你可以绑定名字：

BoundStatement stmt = pStatement.bind()
       .setString("documentId", startDocumentIndex)
       .setInt("documentIndexStart", startDocumentIndex)
       .setInt("documentIndexEnd", endDocumentIndex);

回复于 2024-05-04T00:39:53+08:00

具有范围边界查询的Cassandra BoundStatement

1 回答

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