eClerx Interview Questions, Process, and Tips

To count duplicate values in a table, use the COUNT and GROUP BY functions in SQL.

• Write a SQL query that selects the column with the duplicate values.

• Use the COUNT function to count the number of times each value appears.

• Use the GROUP BY function to group the results by the column with the duplicate values.

• Filter the results to only show values with a count greater than 1.

• Alternatively, use Excel's COUNTIF function to

Optimizing queries involves reducing the time and resources required to retrieve data from a database.

• Use indexes to speed up data retrieval

• Avoid using SELECT * and instead specify the required columns

• Use JOINs instead of subqueries

• Avoid using functions in WHERE clauses

• Limit the number of rows returned using LIMIT

• Use EXPLAIN to analyze query performance

• Normalize the database to reduce redundancy

• Consider using caching m

To fetch multiple rows dynamically in SSRS, use parameters and SQL queries.

• Create a parameter to accept multiple values

• Use the IN operator in SQL query to fetch multiple rows

• Example: SELECT * FROM table WHERE column IN (@parameter)

• Ensure the parameter is set to allow multiple values

• Preview the report to test the dynamic fetching

Bulk reports in SSRS deployment

• Create a data-driven subscription

• Use the Report Manager to upload and deploy the report

• Use PowerShell scripts to automate the deployment process

Group by in SSRS allows grouping of data based on a specific column or expression.

• Grouping can be done in the tablix or matrix data region.

• Grouping can be based on a single column or multiple columns.

• Grouping can also be done based on expressions or custom code.

• Grouping can be used to create subtotals and totals for each group.

• Grouping can also be used to create drilldown reports.

• Examples: Grouping sales data by region

To find 2nd highest salary in SQL, use the ORDER BY and LIMIT clauses.

• Use ORDER BY to sort the salaries in descending order

• Use LIMIT to select the second highest salary

• Example: SELECT salary FROM employees ORDER BY salary DESC LIMIT 1,1

A derivative is a financial contract whose value is based on the performance of an underlying asset or security.

• Types of derivatives include futures, options, swaps, and forwards

• Futures are contracts to buy or sell an asset at a specific price on a specific date

• Options give the holder the right, but not the obligation, to buy or sell an asset at a specific price on or before a specific date

• Swaps involve exchanging cash...read more