How does Power BI handle data import from various sources?

Power BI - Interview Questions

Power BI provides several options for importing data from various sources into its platform. These include:

* DirectQuery : This option allows you to create a live connection to a data source and visualize the data in real-time. No data is stored in Power BI, and all data remains in the source system.

* Import : This option allows you to import a copy of the data into Power BI and store it in the Power BI service. This option is best for small to medium-sized datasets that can be fully loaded into memory.

* Power BI Dataflows : This is a self-service ETL (extract, transform, and load) tool that allows you to connect to and cleanse data from a variety of sources, and then load the data into Power BI.

Here's a simple example of how to import data into Power BI using DirectQuery :

let dataSource = powerbi.data.createDataSource({
   type: "sql",
   connectionString: "Server=<serverName>;Database=<databaseName>;Trusted_Connection=True;",
   table: "Sales"
});

powerbi.datasets.createDataset({
   dataSource: dataSource,
   tables: [{ name: "Sales", columns: [{ name: "Product", type: "string" }, { name: "Amount", type: "decimal" }] }]
})
   .then(function (dataset) {
      let report = powerbi.report({
         data: dataset,
         type: "pie",
         options: {
            dataLabels: {
               fontSize: 20
            },
            legend: {
               visible: false
            }
         }
      });

      powerbi.render(document.getElementById("container"), report);
   });