
Let us take an example into consideration for understanding the usage of the Common Table Expression or CTE and then using it for finding and removing the duplicate entries in the table.
Now let us see how we will find the duplicate rows in a table. We will also discuss Common Table Expression or CTE later in this article also. So, now we have an idea about what Common Table Expression or CTE is.
SQL_statement: The SQL_statement represents the SQL statement for which that particular Common Table Expression or CTE is written and that Common Table Expression or CTE will remain valid till the execution of this SQL statement, such as SELECT INSERT, UPDATE, DELETE, or MERGE. definition_of_CTE: The definition_of_CTE represents the part where the actual definition of the Common Table Expression or CTE will be written. Name_of_column: The name_of_column represents the column or columns on which the Common Table Expression or CTE will be defined. And this name is referred to later in the SQL statement in order to use this Common Table Expression or CTE. Name_of_expression: The name_of_expression represents the name that we want to assign to our Common Table Expression or CTE. The syntax for a Common Table Expression or CTE in SQL Server is: With the help of Common Table Expression or CTE, we can define a temporary named result set that will remain available till the execution of a statement, and that statement can be any statement like SELECT, INSERT, UPDATE, DELETE, or MERGE. In this article, for finding the duplicate rows in a table, we will be using the Common Table Expression, also known as CTE. Now the next step is to write a query that will use the criteria that we have defined in the first step to distinguish the duplicate row in a table. The first operation or step is to define criteria for the duplicates rows in a table that will distinguish that particular duplicate row from the other rows that are present in the same table of the database. Once we have found the duplicate rows successfully, the next step is to use the DELETE statement to remove the duplicate rows.Īs discussed above, the first step is to identify or find the duplicates rows in the table that we want to delete for this, we need to perform some operations, and those operations are:. The first step is to find the duplicate rows with the help of the GROUP BY clause, or we can also use the ROW_NUMBER() function. The various steps that we need to follow in order to find and remove duplicate rows from a table in SQL Server are: Find remove duplicates jaikoz how to#
So, in this article, we are going to see how to find and remove duplicate rows from a table in SQL Server. Sometimes this repetitive date needs to remove from the table to reduce the redundancy of the whole database. Many times, in SQL Server databases there are tables that hold repetitive or the same data.
Next → ← prev Find and Delete Duplicates From a Table in SQL Server