Synechron SQL and PL SQL Developer Interview Questions, Process, and Tips

Developed a database system for a retail company to track inventory and sales

• Designed database schema to store product information, sales data, and customer details

• Implemented stored procedures and triggers to automate inventory updates and sales reports

• Optimized SQL queries for faster data retrieval and analysis

• Challenges faced included handling large volumes of data, ensuring data integrity, and meeting performance r

Types of joins in SQL are Inner Join, Left Join, Right Join, and Full Join.

• Inner Join: Returns rows when there is a match in both tables.

• Left Join: Returns all rows from the left table and the matched rows from the right table.

• Right Join: Returns all rows from the right table and the matched rows from the left table.

• Full Join: Returns rows when there is a match in either table.

Explanation of inner join, left join, right join, and cross join with given tables a and b.

• Inner join: Returns only the rows where there is a match in both tables based on the specified condition.

• Left join: Returns all rows from the left table and the matched rows from the right table. If there is no match, NULL values are returned.

• Right join: Returns all rows from the right table and the matched rows from the left tab...read more

Indexes are data structures that improve the speed of data retrieval operations in a database. There are different types of indexes.

• Indexes are used to quickly locate data without having to search every row in a database table.

• Types of indexes include clustered indexes, non-clustered indexes, unique indexes, and composite indexes.

• Clustered indexes physically reorder the data in the table based on the index key.

• Non-clus...read more

To find department wise highest salary and then 5 highest salaries, use SQL queries with GROUP BY and ORDER BY clauses.

• Use SQL query with GROUP BY clause to get department wise highest salary

• Use ORDER BY clause to get 5 highest salaries overall

row_number assigns a unique sequential integer to each row, rank assigns a unique rank to each row with gaps, dense_rank assigns a unique rank to each row without gaps.

• row_number assigns a unique sequential integer to each row in the result set

• rank assigns a unique rank to each row in the result set with gaps between ranks

• dense_rank assigns a unique rank to each row in the result set without any gaps

Create a table with team names where each team plays with each other once.

• Create a table teams with column teamname

• Insert team names into the table

• Use a combination of team names to represent matches