What is cte? why it’s used

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CTE stands for Common Table Expression. It is used to create a temporary result set that can be referenced within a SELECT, INSERT, UPDATE, or DELETE statement.

CTE is defined using the WITH keyword followed by a name and a SELECT statement.
It can be used to simplify complex queries by breaking them down into smaller, more manageable parts.
CTE can also improve query performance by reducing the number of times a table needs to be scanned.
Example: WITH cte AS (SELECT * FROM myTable) SELECT * FROM cte WHERE column1 = 'value'
Example: WITH recursiveCTE AS (SELECT * FROM myTable WHERE parentID IS NULL UNION ALL SELECT * FROM myTable t JOIN recursiveCTE r ON t.parentID = r.ID) SELECT * FROM recursiveCTE

What is cte? why it’s used

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