Many people and organizations prefer storing data in CSV because of its simplicity, compatibility, and database import/export support. While CSV has its advantages, it also has some drawbacks. For instance, CSV may not be suitable for complex data structures or scenarios where data relationships need to be preserved.
Importing a CSV file into a robust database, such as PostgreSQL, allows you to store data in a reliable and persistent system. By moving data from CSV to PostgreSQL, organizations can leverage powerful SQL queries to organize data, which further enables them to extract insights and make data-driven decisions from the data.
In this comprehensive guide, we’ll cover all the information you need to get started to import CSV file data into a Postgres table and delve deeper into how you can replicate data for your projects.
What Is CSV?
A Comma Separated Value (CSV) file is a lightweight text file used to store data separated by commas with a .csv extension. As data in a CSV file is stored using a comma-delimited format, it’s easier to convert your data into rows and columns. This allows you to conveniently read, edit, and transfer your data to different systems. As a result, CSV file is a popular choice to import and export data between databases for data professionals.
What Is PostgreSQL?
PostgreSQL, also commonly known as Postgres, is an open-source object-relational database management system (ORDBMS). It is a highly scalable database that can be used for both relational (SQL) as well as non-relational (JSON) querying. To help you perform complex operations on tables, PostgreSQL supports different SQL functions, such as user-defined functions, subqueries, and triggers. Because of such flexibility, it is used as a primary database for many web, mobile, and IoT applications.
Here are some key features of PostgreSQL:
- PostgreSQL offers true ACID semantics for transactions.
- It is highly secure and reliable.
- PostgreSQL is free to download and use.
- PostgreSQL supports multiple operating systems, including Linux, Windows, Solaris, OS X, and FreeBSD.
How to Move CSV File Data to PostgreSQL
Using the below methods, you can quickly migrate your data from CSV to PostgreSQL table:
- Method 1: Import CSV to PostgreSQL using no-code data integration tools
- Method 2: Import CSV to PostgreSQL using the Copy command
- Method 3: Import CSV to PostgreSQL using pgAdmin
Method 1: Import CSV to PostgreSQL Using No-Code Data Integration Tools
No-code Cloud ETL tools provide a wide range of pre-built data source and destination connectors to help you move your data between different platforms. Among the top data integration tools for building pipelines, Estuary Flow stands out as a reliable, cost-effective pick.
Flow is a powerful cloud-based data integration platform that can help you move data between different sources and destinations in real time. It allows you to capture data from a CSV hosted at any HTTP endpoint or from Google Sheets. What’s more, you can also use Flow to export data from PostgreSQL to CSV file if needed.
Here’s how you can go about loading data from CSV to PostgreSQL using Estuary Flow:
Step 2: Once you’ve logged in, you'll be redirected to the Estuary dashboard. Click on Sources to set up your source end of the pipeline.
Step 3: On the Sources page, click on the + New Capture button.
Step 4: If your CSV file is hosted at any HTTP endpoint, search HTTP File in the Search Connectors box on the Create Capture page.
Similarly, if you have stored your CSV data in Google Sheets, search for Google Sheets in the Search Connectors box.
Click on the Capture button.
Step 5: You will be redirected to the next page, where you have to fill in Capture Details. If you choose an HTTP file as the source, enter the URL.
If you choose Google Sheets as the source connector, provide a name for the connector and link to your spreadsheet. You can also mention the number of rows you want to fetch.
Step 6: After filling in the Capture Details, click on the Next button, then click on Save and Publish.
Now, you have successfully completed the steps to set up your pipeline's source end. Next, navigate to Destinations on the Estuary dashboard to proceed with the destination setup. Click on the + New Materialization button.
Step 7: Since you're copying your data from CSV to PostgreSQL, search for PostgreSQL in the Search Connectors box. Click on the Materialization button of the PostgreSQL connector. You will be redirected to the PostgreSQL materialization connector page.
Step 8: Before you proceed to connect PostgreSQL, make sure you have completed the prerequisites steps. Once you are done with the necessary steps, you can proceed to set up your destination.
Step 9: On the Create Materialization page, fill in the details such as the Name of the connector, Address, Username, and Password of the database. If your Flow collections aren’t automatically selected for materialization, you can use the Source Collections option to select your collections.
Click on the Next button. Then, click on Save and Publish. After completing these steps, Estuary Flow will continuously replicate your CSV data to PostgreSQL in real time.
BONUS: If you need to load data from Google Sheets to PostgreSQL, check out this handy guide.
Benefits of Moving Data With Estuary Flow
- Real-Time Data Transfer: Estuary Flow uses open-source data connectors that are compatible across platforms and work in real-time. This reduces the repetitive manual efforts to reliably transfer data.
- Scalability and Performance: Flow offers high scalability with performance and ensures you can handle large volumes of data in milliseconds.
Method 2: Import CSV to PostgreSQL Using the Copy Command
Using the COPY command to replicate data from CSV to Postgres is one of the simplest manual methods available. To copy the data, all you need is PostgreSQL superuser access.
The COPY command in PostgreSQL is used to copy data between a PostgreSQL table/database and any source/destination file. Based on your requirement, the COPY command can be used as COPY-TO or COPY-FROM. While COPY-TO copies the data from the table to a specified file, COPY-FROM copies the data from a file to the table.
For a better understanding, let’s consider the following CSV file data and PostgreSQL table.
Step 1: Let’s assume your CSV file data is in the following format:
plaintextStudent ID, First_Name, Last_Name, DOB, City
Step 2: Open the command-line tool in your machine and connect it with your local PostgreSQL server using the following command:
plaintextpsql -U postgres
Step 3: On execution of the above command, you will be prompted to enter the password.
plaintextEnter password: ******
Step 4: Now, you’re connected to the PostgreSQL server. The command prompt will look like this:
Step 5: Create a table in PostgreSQL using the following command:
plaintextcreate table student_info (StudentID SERIAL, First_Name Varchar(50), Last_Name Varchar(50), DOB DATE, City Varchar(50), PRIMARY KEY(StudentID));
On successful execution of the above command, a table name with student_info will be created where StudentID is the primary key.
Step 6: To check the list of databases, enter the below command:
After executing the above command, you can see a list of databases. To check if the table is successfully created in the database, run the \dt command.
Once the PostgreSQL table is ready, you can use the COPY command to move data from CSV to PostgreSQL.
Step 7: To import the CSV file into the PostgreSQL student_info table, use the below COPY command in your command prompt:
plaintextCOPY student_info (StudentID, First_Name, Last_Name, DOB, City) From ‘C:\Program Files\PostgreSQL\Sample1.csv’ DELIMITER ‘,’ CSV HEADER;
The output COPY 4 indicates that all four rows from the CSV file have been copied to your PostgreSQL table.
Let’s understand the above query in more detail:
- COPY-FROM: Used to copy data from a file to the PostgreSQL table.
- student_info: This is the table name where you want to move CSV data. Mentioning column names will copy data from the CSV file to the PostgreSQL table in the given sequence.
- C:\Program Files\PostgreSQL\Sample1.csv: The path and name of the CSV file from where data is to be imported into the PostgreSQL table.
- DELIMITER ‘,’: It defines how the values in the CSV file are separated.
- CSV: Used to specify that data is imported from a CSV file.
- HEADER: Specifies that the CSV file contains a header line with the names of each column. So, the PostgreSQL table will import CSV data from the second row.
Step 8: To check if the tables are imported successfully, run the following command.
plaintextselect * from student_info;
That’s it! You’ve successfully moved CSV file data to the PostgreSQL table. Similarly, you can also use the COPY command to copy PostgreSQL output to CSV.
Method 3: Import CSV to PostgreSQL Using pgAdmin
pgAdmin is an open-source tool for administrating and managing your PostgreSQL databases. You can easily download it from their official website.
Follow the steps below to copy data from CSV to the PostgreSQL table using pgAdmin.
Step 1: With pgAdmin, you can directly create a table using its GUI. In the schema section, go to Tables > Create > Table.
Step 2: You will be redirected to the Create-Table window. Enter the Name and Schema of the table.
Step 3: Now, click on the Save button to create a table.
Step 4: After creating the table, right-click on the table name and select the Import/Export option.
Step 5: An Import/Export Data window with two tabs—Options and Columns—will be opened for that specific table. Select the Options window and enable the Import option from the Import/Export toggle button. Now, mention the path of the file that needs to be imported. Select the format of the file as CSV and specify the delimiter of the file. If your file consists of the headers, enable the header option.
Step 6: Click on the OK button to start the importing process.
You will see a popup window once the data from CSV has been successfully copied to PostgreSQL.
pgAdmin not only allows you to copy data from CSV to PostgreSQL but also lets you make PostgreSQL copy to CSV.
Limitations in Manually Copying CSV to PostgreSQL
While the two manual methods to copy CSV to PostgreSQL are quite simple, there are a few challenges involved.
- Manual methods usually eliminate the scope of cleaning and transforming the data.
- To achieve no loss data transfer, you would need to continuously review and manage the end-to-end data flow. This will require investing your efforts, which can be a time-consuming task.
- For real-time use cases, it would require you to import data manually as soon as the CSV source file data is updated. This will require you to repeat the entire migration process, which can be a tedious task.
Copying CSV to PostgreSQL shouldn’t be a challenging task, especially if you make use of the popular methods used to achieve this (covered in this article). To move data files from CSV to PostgreSQL, you can use the COPY command, pgAdmin, or no-code tools for importing CSV to PostgreSQL.
If you’re considering using a less manual approach, no-code platforms like Estuary, ensure your data remains consistent and up-to-date so that you can automate your data pipeline and focus on your core business objectives.
Estuary Flow allows you to connect data from various sources to PostgreSQL seamlessly. It offers an automated, streamlined solution that helps save both time and hassle. Get integrated, try Flow for free!