Data loader is an application used to insert, upsert, delete or update records in Salesforce and also used to import or export a huge number of data into Salesforce.

When data loader is used in user interface, fields are mapped with the field names in import file to the field names in Salesforce. File format should be in CSV. In another way, we can use the command line by specifying data sources, mappings and actions in files. We can automate the data loader by this way.

If you want to upload less than 50,000 records into Salesforce, we can use import wizard, which appears in the data management. But, when more than 50,000 records needed to be uploaded, we use data loader. By this way, we can upload upto five million records into Saleforce.

Install Data Loader:

In Setup --> Data management --> Data loader

Click on download for windows if you are using windows or download for mac if you're using a mac.

Upon clicking the selected format, installation file will be downloaded and with that data loader can be installed.

How to use Data loader:

Data loader consists of options like insert, delete, update, upsert, hard delete, export and export all.

To do any of the above operations, we need to login to the salesforce account by providing the security token along with the account password. Only after logging into the account, we can perform the required operations.

To Insert records into salesforce, click on insert, provide login details and select the object to which you want to insert the records.

Select the .csv file(inserting file) and map the fields in the csv file to the fields in the object and finish the insertion by clicking on the next. We can save the mapping for the further usage.

In Upsert, we can insert the records and update the existing records by mapping the fields correctly to the fields in object.

In Delete, we can delete the records in organization like upon selecting delete option and logging into the account then select the object, select the csv file to match the id's you want to delete, map the fields and click on next.

In Hard Delete, it refers to delete the data permanently from the organization like deleting data from a recycle bin. To enable this option, we need to enable bulk API in the data loader settings.

Export and Export all are used to get the data of an object in salesforce account and saved in .csv file. Upon clicking the Export option, choose the object and browse the csv file to save the data of that  object. By clicking Export all it allows to get the data of that object from the recycle bin. Hence in this option entire data of the object can be downloaded.

We can use data loader to upload attachments as well. To upload attachments, select upload bulk api batch as a zip file in the data loader settings.

Upon selecting the above option, we can do bulk upload of documents and links into libraries of Salsforce CRM.

After importing or exporting, data loader gives two output files, which contains success and errors. We can view these success and error files.

Note:

Only dates with certain range are accepted for mapping according to the Salesforce limits.

To view in detail about any operations done in data loader, you can view them in data loader log file.