Planetcast Software Engineer Interview Questions and Answers

Clustered index determines the physical order of data in a table, while non-clustered index has a separate structure.

• Clustered index sorts and stores the data rows in the table based on their key values, while non-clustered index has a separate structure that contains the key values and a pointer to the data row.

• A table can have only one clustered index, while it can have multiple non-clustered indexes.

• Clustered index is faster for retrieving large amounts of data, while non-...read more

ExecuteScalar returns single value while ExecuteNonQuery does not return any value.

• ExecuteScalar is used for retrieving a single value from the database, such as a count or sum.

• ExecuteNonQuery is used for executing SQL statements that do not return any value, such as INSERT, UPDATE, DELETE.

• ExecuteScalar returns the first column of the first row of the result set, while ExecuteNonQuery returns the number of rows affected by the query.

• ExecuteScalar is faster than ExecuteNonQuer...read more

Rank assigns unique numbers to each distinct value, while dense rank assigns consecutive numbers to each distinct value.

• Rank and DenseRank are used to assign a unique number to each distinct value in a sorted list.

• Rank assigns a unique number to each distinct value, but leaves gaps for ties.

• DenseRank assigns consecutive numbers to each distinct value, without leaving gaps for ties.

• In C#, Rank and DenseRank are available as LINQ extension methods.

• Example: Given a list of score...read more

Functions return a value while stored procedures do not.

• Functions are used to perform a specific task and return a value to the caller.

• Stored procedures are used to execute a set of statements and do not return a value.

• Functions can be used in SQL statements while stored procedures cannot.

• Functions can be called from within stored procedures.

• Functions can be used in expressions while stored procedures cannot.

IEnumerable is read-only and forward-only while IQueryable is queryable and can be filtered.

• IEnumerable is used for in-memory collections while IQueryable is used for querying databases.

• IQueryable is more efficient for large datasets as it allows for server-side filtering.

• IQueryable extends IEnumerable and adds additional functionality for querying data sources.

• Example: IEnumerable numbers = new List { 1, 2, 3 }; IQueryable queryableNumbers = numbers.AsQueryable();