The role and usage of SQL over

the role and usage of SQL over rank () Over([Query_partition_clause]order_by_clause) Dense_rank () Over([Query_partition_clause]order_by_clause) enables sorting by the specified field grouping for the result set of the same grouping field, where partition byis a grouping field,ORDER  bySpecifies the sort field over cannot be used alone, to be used with analytic functions: Rank (), Dense_rank (), Row_number (), and so on. Its parameters: Over(Partition byColumnname1Order  bycolumnname2) Meaning: Sort by the field specified by Columname1, or by the value of the field columnname1. For example: In the Employees table, there are two records for the department: department_id = 10 andSelectDepartment_id,rank () Over(Partition bydepartment_idOrder  bySalary fromEmployees refers to the rank of salary in department 10, and the salary rank in department 20. If it's partition, byORG_ID is ranked throughout the company.

The role and usage of SQL over