Loading TSV File into Databend

What is TSV?

TSV (Tab Separated Values) is a simple file format used to store tabular data, such as a spreadsheet or database. The TSV file format is very similar to CSV, the records are separated by newlines, and each field is separated by a tab. The following example shows a TSV file with two records:

Title_0 Author_0
Title_1 Author_1

Loading TSV File

The common syntax for loading TSV file is as follows:

COPY INTO [<database>.]<table_name>
FROM { userStage | internalStage | externalStage | externalLocation }
[ PATTERN = '<regex_pattern>' ]
[ FILE_FORMAT = (
    TYPE = TSV,
    SKIP_HEADER = <integer>,
    COMPRESSION = AUTO
) ]

More details about the syntax can be found in COPY INTO <table>.

Tutorial: Loading Data from TSV Files

Step 1. Create an Internal Stage

Create an internal stage to store the TSV files.

CREATE STAGE my_tsv_stage;

Step 2. Create TSV files

Generate a TSV file using these SQL statements:

COPY INTO @my_tsv_stage 
FROM (
    SELECT 
        'Title_' || CAST(number AS VARCHAR) AS title,
        'Author_' || CAST(number AS VARCHAR) AS author
    FROM numbers(100000)
)
    FILE_FORMAT = (TYPE = TSV)
;

Verify the creation of the TSV file:

LIST @my_tsv_stage;

Result:

┌───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│                             name                            │   size  │                 md5                │         last_modified         │      creator     │
├─────────────────────────────────────────────────────────────┼─────────┼────────────────────────────────────┼───────────────────────────────┼──────────────────┤
│ data_7413d5d0-f992-4d92-b28e-0e501d66bdc1_0000_00000000.tsv │ 2477780 │ "a906769144de7aa6a0056a86ddae97d2" │ 2023-12-26 11:56:19.000 +0000 │ NULL             │
└───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

Step 3: Create Target Table

CREATE TABLE books
(
    title VARCHAR,
    author VARCHAR
);

Step 4. Copying Directly from TSV

To directly copy data into your table from TSV files, use the following SQL command:

COPY INTO books
FROM @my_tsv_stage
PATTERN = '.*[.]tsv'
FILE_FORMAT = (
    TYPE = TSV,
    SKIP_HEADER = 0, -- Skip the first line if it is a header, here we don't have a header
    COMPRESSION = AUTO
);

Result:

┌───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│                             File                            │ Rows_loaded │ Errors_seen │    First_error   │ First_error_line │
├─────────────────────────────────────────────────────────────┼─────────────┼─────────────┼──────────────────┼──────────────────┤
│ data_7413d5d0-f992-4d92-b28e-0e501d66bdc1_0000_00000000.tsv │      100000 │           0 │ NULL             │             NULL │
└───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

Step 4 (Option). Using SELECT to Copy Data

For more control, like transforming data while copying, use the SELECT statement. Learn more at SELECT from TSV.

COPY INTO books (title, author)
FROM (
    SELECT $1, $2 
    FROM @my_tsv_stage
)
PATTERN = '.*[.]tsv'
FILE_FORMAT = (
    TYPE = 'TSV',
    SKIP_HEADER = 0, -- Skip the first line if it is a header, here we don't have a header
    COMPRESSION = 'AUTO'
);