please any help for SQL Query???

1) Find employee names whose last name start either with a D or C and second last character of first name is either an e or a n. 2) List the department name with the least number of employees. 3) List pair of employee names who are having the same qualification order by qualification id. 4) Display each employees name, department name, position description, and qualification description. Which employee is missing? Why? 5) Find the average (two decimal point), highest, lowest and total salary for each department.Name the colomn Average Salary, Maximum Salary and Minimum Salary and Total Salary. Also display the department id.

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