Package com.databend.jdbc

Interface DatabendConnectionExtension

All Known Implementing Classes:

DatabendConnection

public interface DatabendConnectionExtension

The SnowflakeConnection interface contains Snowflake-specific methods. providing specialized methods for interacting with Databend stages and loading data efficiently.

This interface extends standard JDBC connection capabilities to support streaming operations for uploading/downloading files to/from internal stages, as well as direct streaming data loading into target tables. Ideal for handling large files or continuous data streams in Databend.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	DatabendConnectionExtension.LoadMethod	Enumeration of available loading strategies for streaming data into tables.

Method Summary

Modifier and Type	Method	Description
InputStream	downloadStream(String stageName, String sourceFileName)	Download a file from the databend internal stage, the data would be downloaded as one file with no split.
int	loadStreamToTable(String sql, InputStream inputStream, long fileSize, DatabendConnectionExtension.LoadMethod loadMethod)	Loads data from an input stream directly into a target Databend table using the specified SQL command.
void	uploadStream(InputStream inputStream, String stageName, String destPrefix, String destFileName, long fileSize, boolean compressData)	Upload inputStream to the databend internal stage, the data would be uploaded as one file with no split.
void	uploadStream(String stageName, String destPrefix, InputStream inputStream, String destFileName, long fileSize, boolean compressData)

Method Detail

uploadStream

void uploadStream(String stageName,
                  String destPrefix,
                  InputStream inputStream,
                  String destFileName,
                  long fileSize,
                  boolean compressData)
           throws SQLException

Throws:

SQLException

uploadStream

void uploadStream(InputStream inputStream,
                  String stageName,
                  String destPrefix,
                  String destFileName,
                  long fileSize,
                  boolean compressData)
           throws SQLException

Upload inputStream to the databend internal stage, the data would be uploaded as one file with no split. Caller should close the input stream after the upload is done.

Parameters:

stageName - the stage which receive uploaded file

destPrefix - the prefix of the file name in the stage

inputStream - the input stream of the file

destFileName - the destination file name in the stage

fileSize - the file size in the stage

compressData - whether to compress the data

Throws:

SQLException - failed to upload input stream

downloadStream

InputStream downloadStream(String stageName,
                           String sourceFileName)
                    throws SQLException

Download a file from the databend internal stage, the data would be downloaded as one file with no split.

Parameters:

stageName - the stage which contains the file

sourceFileName - the file name in the stage

Returns:

the input stream of the file

Throws:

SQLException - failed to download input stream

loadStreamToTable

int loadStreamToTable(String sql,
                      InputStream inputStream,
                      long fileSize,
                      DatabendConnectionExtension.LoadMethod loadMethod)
               throws SQLException

Loads data from an input stream directly into a target Databend table using the specified SQL command. Supports two loading strategies via DatabendConnectionExtension.LoadMethod.

Parameters:

sql - SQL command with Databend's load syntax: INSERT INTO <table> [(<columns>)] FROM @_databend_load [file_format=(...)]

inputStream - Input stream containing the data to load into the table

fileSize - Size of the data (in bytes) to be loaded

loadMethod - Loading strategy (DatabendConnectionExtension.LoadMethod.STAGE or DatabendConnectionExtension.LoadMethod.STREAMING)

Returns:

Number of rows successfully loaded into the target table

Throws:

SQLException - If the load operation fails (e.g., invalid SQL, stream errors, or data format issues)