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Loading from a Local File

In this tutorial, you will load data from a local sample file into Databend with the BendSQL.

Tutorial 1 - Load from a CSV File​

This tutorial takes a CSV file as an example, showing how to load data into Databend from a local file.

Before You Begin​

Download the sample CSV file books.csv. The sample contains the following records:

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

Step 1. Create Database and Table​

> bendsql
Welcome to BendSQL.
Trying connect to localhost:8000 as user root.
Connected to DatabendQuery v1.1.2-nightly-8ade21e4669e0a2cc100615247705feacdf76c5b(rust-1.70.0-nightly-2023-04-15T16:08:52.195357424Z)

root@localhost> CREATE DATABASE book_db;
Processed in (0.020 sec)

root@localhost> use book_db;

USE book_db

0 row in 0.020 sec. Processed 0 rows, 0B (0 rows/s, 0B/s)

root@localhost> CREATE TABLE books
(
    title VARCHAR,
    author VARCHAR,
    date VARCHAR
);
Processed in (0.029 sec)

root@localhost>

Step 2. Load Data into Table​

Send loading data request with the following command:

> bendsql --query='INSERT INTO book_db.books VALUES;' --format=csv --data=@books.csv --progress
==> Stream Loaded books.csv:
    Written 2 (24.29 rows/s), 157B (1.86 KiB/s)

Step 3. Verify Loaded Data​

> echo "SELECT * FROM books;" | bendsql --database book_db
┌─────────────────────────────────────────────────────────────┐
│             title            │        author       │  date  │
│            String            │        String       │ String │
├──────────────────────────────┼─────────────────────┼────────┤
│ Transaction Processing       │ Jim Gray            │ 1992   │
│ Readings in Database Systems │ Michael Stonebraker │ 2004   │
└─────────────────────────────────────────────────────────────┘

Tutorial 2 - Load into Specified Columns​

In Tutorial 1, you created a table containing three columns that exactly match the data in the sample file. The Streaming Load API also allows you to load data into specified columns of a table in Databend, so the table does not need to have the same columns as the data to be loaded as long as the specified columns can match. This tutorial shows how to do that.

Before You Begin​

Before you start this tutorial, make sure you have completed Tutorial 1.

Step 1. Create Table​

Create a table including an extra column named "comments" compared to the table "books":

CREATE TABLE bookcomments
(
    title VARCHAR,
    author VARCHAR,
    comments VARCHAR,
    date VARCHAR
);

Step 2. Load Data into Table​

Send loading data request with the following command:

> bendsql --query='INSERT INTO book_db.bookcomments(title,author,date) VALUES;' --format=csv --data=@books.csv --progress
==> Stream Loaded books.csv:
    Written 2 (23.23 rows/s), 221B (2.51 KiB/s)

Notice that the query part above specifies the columns (title, author, and date) to match the loaded data.

Step 3. Verify Loaded Data​

SELECT * FROM bookcomments;

┌────────────────────────────────────────────────────────────────────────┐
│             title            │        author       │ comments │  date  │
│            String            │        String       │  String  │ String │
├──────────────────────────────┼─────────────────────┼──────────┼────────┤
│ Transaction Processing       │ Jim Gray            │          │ 1992   │
│ Readings in Database Systems │ Michael Stonebraker │          │ 2004   │
└────────────────────────────────────────────────────────────────────────┘

2 rows in 0.033 sec. Processed 2 rows, 2B (60.42 rows/s, 7.14 KiB/s)