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Database integration is an essential aspect of any data management system. In Databricks, we can connect to various external sources, such as databases, and use SQL language for data manipulation and retrieval. If you’re a data analyst or data scientist familiar with SQL and want to leverage your skills in Databricks, this guide is for you.
Connection to External Data Sources
Before executing any SQL query, you must first establish a connection to your database. Databricks offers various built-in methods to connect to external data sources. Below shows a typical connection string to an external database:
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CREATE DATABASE db_name LOCATION 'dbfs:/mnt/databases/db_name.db' OPTIONS ( path 'jdbc:sqlserver://[address]:[port];database=[databaseName];user=[userName];password=[password]'); |
Replace the ‘db_name’ with your actual database name, ‘[address]’ with the IP address or domain, ‘[port]’ with the port number, ‘[databaseName]’ with the name of your database, ‘[username]’ and ‘[password]’ with the corresponding login credentials.
Loading Data from Your Database
Upon creating a successful connection, to load data from your database to a DataFrame in Databricks, use the following SQL command:
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CREATE TABLE new_table USING org.apache.spark.sql.jdbc OPTIONS ( url 'jdbc:postgresql:dbserver', dbtable 'schema.tablename'); |
Here, ‘new_table’ will be the DataFrame where your database table data will be loaded, ‘dbserver’ is your database server name, ‘schema.tablename’ is the name of your database schema and table.
SQL Queries in Databricks
You can run standard SQL queries in Databricks like any other platform. Below is an example of a simple query:
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SELECT * FROM my_table |
In Databricks, SQL language supports the majority of constructs from ANSI SQL:2003.
Conclusion
By enabling SQL data integration in Databricks, you can leverage your SQL skills to query your data efficiently, summarise it and draw insights. Connecting Databricks to external data sources opens up more opportunities for handling and manipulating bigger datasets.