SQL PRACTICE: SQL SERVER - Find Duplicate Rows

 Q8. How to find duplicate rows using SQL?


N.B: I am using the following:

Database -> MSSQL

SQL Dialect -> T-SQL

I have a table given below:

Table1. Employees Table

To find duplicate records from the table, we are going to use to use aggregate functions such as count and having.
select 
EmpId,
count(*) as Count
from employees
group by EmpId
having count(*) >=2;  
Table 2. Duplicate Rows





Comments

Post a Comment

Popular posts from this blog

SQL PRACTICE: SQL SERVER - DATEADD Function

Image
  Q12. Find the join date of employees   if they  join after 2 weeks of the hire date? N.B: I am using the following: Database: MSSQL SQL Dialect: T-SQL  Consider below table (Sql_data) as a source data. select * from Sql_data; Table 1. Source Data -- Find the join date of employees select      empid,  FirstName,  LastName, DOB, Hire_date, DATEADD(WK, 2, Hire_date) as Join_date, Salary from Sql_data; Table 2. Join Date Explanation :  DATEADD  function adds a number to a datepart and returns a modified  value based on a   specified  datepart  (Year, Month, Week, Day …..etc...).  Syntax: DATEADD (datepart, NumberToAdd, Date) Parameters: datepart -  It is part of the date to which the dateadd () function will add a number. It can be Year(YY, YYYY), Quarter(QQ, Q), month(MM,M), day(DD, D), …..etc....  In our case, we are going to use Week (WK) NumberToAdd -  It is an ...
Read more

SQL PRACTICE: SQL SERVER - Unique Records

Image
 Q2: How to select unique values in SQL? N.B: I am using the following: Database: MSSQL SQL Dialect: T-SQL  Below is an employee table given. It has 3 fields and 7 records.                                                       Table1: Employee Table To find unique values of the table, I am going to use three different ways:  1. Using distinct clause select distinct EmpId, Name, Salary from employee; Table2: Distinct Clause Method 2. Using Group by (Without using distinct keyword) select EmpId, Name, Salary from employee group by EmpId, Name, Salary; Table3. Group By Method 3. Using Row_Number Function select Empid, Name, Salary , ROW_NUMBER() over(partition by empid, Name,  Salary order by empid) as Row_Num from employee; Result: Table4. Row_Number Function Row_number is used to give a unique number for each row as you can see from ta...
Read more

SQL PRACTICE: SQL SERVER: DATEDIFF Function

Image
 Q11. Find the age of employees from the provided table using SQL? N.B: I am using the following: Database: MSSQL SQL Dialect: T-SQL  Consider below table (Sql_data) as a source data. select * from Sql_data; Table 1. Source Data -- Find the age of employees select      empid,  FirstName,  LastName, DOB,  DATEDIFF(YY, DOB, GETDATE()) as Age from Sql_data;                                                                      Table 2. Age of Employees Explanation : DATEDIFF function is used to return the date difference between two dates according to the date part specified (Year, Month, Day …..etc...).  Syntax: DATEDIFF(datepart, Date1, Date2) Parameters: datepart - Used to get the time difference between the two dates. It can be Year(YY, YYYY), Quarter(QQ , Q)...
Read more