Snowflake in 20 Minutes¶

Introduction¶

This tutorial uses the Snowflake command line client, SnowSQL, to introduce key concepts and tasks, including:

• Creating Snowflake objects—You create a database and a table, for storing data.

• Loading data—Small sample CSV data files are provided for you to load into the table.

• Querying—Finally, you explore sample queries.

Prerequisites¶

This tutorial requires a database, table, and virtual warehouse to load and query data. Creating these Snowflake objects requires a Snowflake user with a role with the necessary access control privileges. In addition, SnowSQL is required to execute the SQL statements in the tutorial. Lastly, the tutorial requires CSV files containing sample data to load.

You can complete this tutorial using an existing Snowflake warehouse, database and table, and your own local data files but we recommend using the Snowflake objects and the set of provided data.

To set up Snowflake for this tutorial, complete the following before continuing:

1. Create a user

   To create the database, table, and virtual warehouse, you must be logged in as a Snowflake user with a role that grants you the privileges to create these objects.

   • If you are using a 30-day trial account, you can log in as the user that was created for the account. This user has the role with the privileges needed to create the objects.

   • If you don’t have a snowflake user you can’t perform this tutorial. If you don’t have a role that lets you create a user, ask someone who does to perform this step for you. Users with the ACCOUNTADMIN or SECURITYADMIN role can create users.

2. Install SnowSQL

   To install SnowSQL, see Installieren von SnowSQL.

3. Download sample data files

   For this tutorial you wil download sample employee data files in CSV format provided by Snowflake.

   To download and unzip the sample data files:

   1. Download the set of sample data files. Right-click the name of the archive file, getting-started.zip and save the link/file to your local file system.

   2. Unzip the sample files. The tutorial assumes you unpacked files into one of the following directories:

   • Linux/macOS: /tmp

   • Windows: C:\\temp

   Each file has five data records. The data uses a comma (,) character as field delimiter. An example record is shown:

   Althea,Featherstone,afeatherstona@sf_tuts.com,"8172 Browning Street, Apt B",Calatrava,7/12/2017
   

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There are no blank spaces before or after the commas separating the fields in each record. This is the default that Snowflake expects when loading CSV data.

Log in to SnowSQL¶

After you have SnowSQL, start SnowSQL to connect to Snowflake:

1. Open a command line window.

2. Start SnowSQL:

   $ snowsql -a <account_identifier> -u <user_name>
   

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   Where:

   • <account_identifier>

     Unique identifier for your Snowflake account.

     The preferred format of the account identifier is as follows:

     organization_name-account_name

     Names of your Snowflake organization and account. For details, see Format 1 (bevorzugt): Kontoname in Ihrer Organisation.

   • <user_name> is the login name for your Snowflake user.

   Bemerkung

   If your account has an identity provider (IdP) that has been defined for your account, you may use a web browser to authenticate instead of a password, as the following example demonstrates.

   $ snowsql -a <account_identifier> -u <user_name> --authenticator externalbrowser
   

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   For more information, refer to Verwenden eines Webbrowsers für Verbundauthentifizierung/SSO.

3. When prompted by SnowSQL, enter the password for your Snowflake user.

If you log in successfully, SnowSQL displays a command prompt that includes your current warehouse, database, and schema.

If your Snowflake user does not have a default warehouse, database, and schema, or if you did not configure SnowSQL to specify a default warehouse, database, and schema, the prompt displays no warehouse, no database, and no schema. For example:

user-name#(no warehouse)@(no database).(no schema)>

This prompt indicates that there is no warehouse, database, and schema selected for the current session. You create these objects in the next step. As you follow the next steps in this tutorial to create these objects, the prompt automatically updates to include the names of these objects.

For more details, see Verbinden über SnowSQL.

Create Snowflake objects¶

During this step you will create the following Snowflake objects:

• A database (sf_tuts) and a table (emp_basic). You load sample data into this table.

• A virtual warehouse (sf_tuts_wh). This warehouse provides the compute resources needed to load data into the table and query the table. For this tutorial, you create an X-Small warehouse.

At the completion of this tutorial, you will remove these objects.

CREATE OR REPLACE DATABASE sf_tuts;

SELECT CURRENT_DATABASE(), CURRENT_SCHEMA();

+--------------------+------------------+
| CURRENT_DATABASE() | CURRENT_SCHEMA() |
|--------------------+------------------|
| SF_TUTS            | PUBLIC           |
+--------------------+------------------+

CREATE OR REPLACE TABLE emp_basic (
   first_name STRING ,
   last_name STRING ,
   email STRING ,
   streetaddress STRING ,
   city STRING ,
   start_date DATE
   );

CREATE OR REPLACE WAREHOUSE sf_tuts_wh WITH
   WAREHOUSE_SIZE='X-SMALL'
   AUTO_SUSPEND = 180
   AUTO_RESUME = TRUE
   INITIALLY_SUSPENDED=TRUE;

SELECT CURRENT_WAREHOUSE();

+---------------------+
| CURRENT_WAREHOUSE() |
|---------------------|
| SF_TUTS_WH          |
+---------------------+

Stage data files¶

A Snowflake stage is a location in cloud storage that you use to load and unload data from a table. Snowflake supports:

• Internal stages—Used to store data files internally within Snowflake. Each user and table in Snowflake gets an internal stage by default for staging data files.

• External stages—Used to store data files externally in Amazon S3, Google Cloud Storage, or Microsoft Azure. If your data is already stored in these cloud storage services, you can use an external stage to load data in Snowflake tables.

In this tutorial, we upload the sample data files (downloaded in Prerequisites) to the internal stage for the emp_basic table that you created earlier. You use the PUT command to upload the sample data files to that stage.

PUT file://<file-path>[/\]employees0*.csv @sf_tuts.public.%emp_basic;

+-----------------+--------------------+-------------+-------------+--------------------+--------------------+----------+---------+
| source          | target             | source_size | target_size | source_compression | target_compression | status   | message |
|-----------------+--------------------+-------------+-------------+--------------------+--------------------+----------+---------|
| employees01.csv | employees01.csv.gz |         360 |         287 | NONE               | GZIP               | UPLOADED |         |
| employees02.csv | employees02.csv.gz |         355 |         274 | NONE               | GZIP               | UPLOADED |         |
| employees03.csv | employees03.csv.gz |         397 |         295 | NONE               | GZIP               | UPLOADED |         |
| employees04.csv | employees04.csv.gz |         366 |         288 | NONE               | GZIP               | UPLOADED |         |
| employees05.csv | employees05.csv.gz |         394 |         299 | NONE               | GZIP               | UPLOADED |         |
+-----------------+--------------------+-------------+-------------+--------------------+--------------------+----------+---------+

LIST @sf_tuts.public.%emp_basic;

+--------------------+------+----------------------------------+------------------------------+
| name               | size | md5                              | last_modified                |
|--------------------+------+----------------------------------+------------------------------|
| employees01.csv.gz |  288 | a851f2cc56138b0cd16cb603a97e74b1 | Tue, 9 Jan 2018 15:31:44 GMT |
| employees02.csv.gz |  288 | 125f5645ea500b0fde0cdd5f54029db9 | Tue, 9 Jan 2018 15:31:44 GMT |
| employees03.csv.gz |  304 | eafee33d3e62f079a054260503ddb921 | Tue, 9 Jan 2018 15:31:45 GMT |
| employees04.csv.gz |  304 | 9984ab077684fbcec93ae37479fa2f4d | Tue, 9 Jan 2018 15:31:44 GMT |
| employees05.csv.gz |  304 | 8ad4dc63a095332e158786cb6e8532d0 | Tue, 9 Jan 2018 15:31:44 GMT |
+--------------------+------+----------------------------------+------------------------------+

Copy data into target tables¶

To load your staged data into the target table, execute COPY INTO <Tabelle>.

The COPY INTO <Tabelle> command uses the virtual warehouse you created in Create Snowflake objects to copy files.

COPY INTO emp_basic
  FROM @%emp_basic
  FILE_FORMAT = (type = csv field_optionally_enclosed_by='"')
  PATTERN = '.*employees0[1-5].csv.gz'
  ON_ERROR = 'skip_file';

Where:

• The FROM clause specifies the location containing the data files (the internal stage for the table).

• The FILE_FORMAT clause specifies the file type as CSV, and specifies the double-quote character (") as the character used to enclose strings. Snowflake supports diverse file types and options. These are described in CREATE FILE FORMAT.

• The PATTERN clause specifies that the command should load data from the filenames matching this regular expression (.*employees0[1-5].csv.gz).

• The ON_ERROR clause specifies what to do when the COPY command encounters errors in the files. By default, the command stops loading data when the first error is encountered. This example skips any file containing an error and moves on to loading the next file. None of the files in this tutorial contain errors, this is included for illustration purposes.

The COPY command also provides an option for validating files before they are loaded. See the COPY INTO <Tabelle> topic and the other data loading tutorials for additional error checking and validation instructions.

The COPY command returns a result showing the list of files copied and related information:

+--------------------+--------+-------------+-------------+-------------+-------------+-------------+------------------+-----------------------+-------------------------+
| file               | status | rows_parsed | rows_loaded | error_limit | errors_seen | first_error | first_error_line | first_error_character | first_error_column_name |
|--------------------+--------+-------------+-------------+-------------+-------------+-------------+------------------+-----------------------+-------------------------|
| employees02.csv.gz | LOADED |           5 |           5 |           1 |           0 | NULL        |             NULL |                  NULL | NULL                    |
| employees04.csv.gz | LOADED |           5 |           5 |           1 |           0 | NULL        |             NULL |                  NULL | NULL                    |
| employees05.csv.gz | LOADED |           5 |           5 |           1 |           0 | NULL        |             NULL |                  NULL | NULL                    |
| employees03.csv.gz | LOADED |           5 |           5 |           1 |           0 | NULL        |             NULL |                  NULL | NULL                    |
| employees01.csv.gz | LOADED |           5 |           5 |           1 |           0 | NULL        |             NULL |                  NULL | NULL                    |
+--------------------+--------+-------------+-------------+-------------+-------------+-------------+------------------+-----------------------+-------------------------+

Query loaded data¶

You can query the data loaded in the emp_basic table using standard SQL and any supported functions and operators.

You can also manipulate the data, such as updating the loaded data or inserting more data, using standard DML commands.

SELECT * FROM emp_basic;

+------------+--------------+---------------------------+-----------------------------+--------------------+------------+
| FIRST_NAME | LAST_NAME    | EMAIL                     | STREETADDRESS               | CITY               | START_DATE |
|------------+--------------+---------------------------+-----------------------------+--------------------+------------|
| Arlene     | Davidovits   | adavidovitsk@sf_tuts.com  | 7571 New Castle Circle      | Meniko             | 2017-05-03 |
| Violette   | Shermore     | vshermorel@sf_tuts.com    | 899 Merchant Center         | Troitsk            | 2017-01-19 |
| Ron        | Mattys       | rmattysm@sf_tuts.com      | 423 Lien Pass               | Bayaguana          | 2017-11-15 |
 ...
 ...
 ...
| Carson     | Bedder       | cbedderh@sf_tuts.co.au    | 71 Clyde Gallagher Place    | Leninskoye         | 2017-03-29 |
| Dana       | Avory        | davoryi@sf_tuts.com       | 2 Holy Cross Pass           | Wenlin             | 2017-05-11 |
| Ronny      | Talmadge     | rtalmadgej@sf_tuts.co.uk  | 588 Chinook Street          | Yawata             | 2017-06-02 |
+------------+--------------+---------------------------+-----------------------------+--------------------+------------+

INSERT INTO emp_basic VALUES
   ('Clementine','Adamou','cadamou@sf_tuts.com','10510 Sachs Road','Klenak','2017-9-22') ,
   ('Marlowe','De Anesy','madamouc@sf_tuts.co.uk','36768 Northfield Plaza','Fangshan','2017-1-26');

SELECT email FROM emp_basic WHERE email LIKE '%.uk';

+--------------------------+
| EMAIL                    |
|--------------------------|
| gbassfordo@sf_tuts.co.uk |
| rtalmadgej@sf_tuts.co.uk |
| madamouc@sf_tuts.co.uk   |
+--------------------------+

SELECT first_name, last_name, DATEADD('day',90,start_date) FROM emp_basic WHERE start_date <= '2017-01-01';

+------------+-----------+------------------------------+
| FIRST_NAME | LAST_NAME | DATEADD('DAY',90,START_DATE) |
|------------+-----------+------------------------------|
| Granger    | Bassford  | 2017-03-30                   |
| Catherin   | Devereu   | 2017-03-17                   |
| Cesar      | Hovie     | 2017-03-21                   |
| Wallis     | Sizey     | 2017-03-30                   |
+------------+-----------+------------------------------+

Summary, clean up, and additional resources¶

Congratulations! You have successfully completed this introductory tutorial.

Take a few minutes to review a short summary and the key points covered in the tutorial. You might also want to consider cleaning up by dropping any objects you created in the tutorial. Learn more by reviewing other topics in the Snowflake Documentation.

DROP DATABASE IF EXISTS sf_tuts;

DROP WAREHOUSE IF EXISTS sf_tuts_wh;