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Loading from an Internal Stage

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In this tutorial, you will create an internal stage, stage a sample file, and then load data from the file into Databend with the COPY INTO command.

Step 1. Create Stage Object

Execute CREATE STAGE to create a named internal stage.

mysql -h127.0.0.1 -uroot -P3307
CREATE STAGE my_int_stage;
DESC STAGE my_int_stage;
+--------------+------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------------------+--------------------------------------------------------------------------------------------------------------------+---------+
| name | stage_type | stage_params | copy_options | file_format_options | comment |
+--------------+------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------------------+--------------------------------------------------------------------------------------------------------------------+---------+
| my_int_stage | Internal | StageParams { storage: S3(StageS3Storage { bucket: "", path: "", credentials_aws_key_id: "", credentials_aws_secret_key: "", encryption_master_key: "" }) } | CopyOptions { on_error: None, size_limit: 0 } | FileFormatOptions { format: Parquet, skip_header: 0, field_delimiter: ",", record_delimiter: "\n", compression: None } | |
+--------------+------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------------------+--------------------------------------------------------------------------------------------------------------------+---------+

Step 2. Stage the Data Files

Download the sample data file(Choose CSV or Parquet), the file contains two records:

Transaction Processing,Jim Gray,1992
Readings in Database Systems,Michael Stonebraker,2004

Download books.csv

Upload books.csv into stages:

Request /v1/upload_to_stage
curl -H "stage_name:my_int_stage"\
-F "upload=@./books.csv"\
-XPUT http://root:@localhost:8000/v1/upload_to_stage
Response
{"id":"50880048-f397-4d32-994c-ce3d38af430f","stage_name":"my_int_stage","state":"SUCCESS","files":["books.csv"]}
tip
  • http://127.0.0.1:8000/v1/upload_to_stage

    • 127.0.0.1 is http_handler_host value in your databend-query.toml
    • 8000 is http_handler_port value in your databend-query.toml
  • -F \"upload=@./books.csv\"

    • Your books.csv file location

Step 3. List the Staged Files (Optional)

mysql -h127.0.0.1 -uroot -P3307
LIST @my_int_stage;
+---------------+------+------+-------------------------------+--------------------+
| name | size | md5 | last_modified | creator |
+---------------+------+------+-------------------------------+--------------------+
| books.csv | 91 | NULL | 2022-06-10 12:01:40.000 +0000 | 'root'@'127.0.0.1' |
| books.parquet | 91 | NULL | 2022-06-10 12:01:40.000 +0000 | 'root'@'127.0.0.1' |
+---------------+------+------+-------------------------------+--------------------+

Step 4. Creating Database and Table

CREATE DATABASE book_db;
USE book_db;
CREATE TABLE books
(
title VARCHAR,
author VARCHAR,
date VARCHAR
);

Step 5. Copy Data into the Target Tables

Execute COPY to load staged files to the target table.

COPY INTO books FROM @my_int_stage files=('books.csv') file_format = (type = CSV field_delimiter = ','  record_delimiter = '\n' skip_header = 0);
tip
  • files = ( 'file_name' [ , 'file_name' ... ] )

    Specifies a list of one or more files names (separated by commas) to be loaded.

  • file_format
ParametersDescriptionRequired
record_delimiterOne characters that separate records in an input file. Default '\n'Optional
field_delimiterOne characters that separate fields in an input file. Default ','Optional
skip_headerNumber of lines at the start of the file to skip. Default 0Optional

Step 6. Verify the Loaded Data

SELECT * FROM books;
+------------------------------+----------------------+-------+
| title | author | date |
+------------------------------+----------------------+-------+
| Transaction Processing | Jim Gray | 1992 |
| Readings in Database Systems | Michael Stonebraker | 2004 |
+------------------------------+----------------------+-------+