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Window functions

Window functions perform calculations using values from multiple rows to produce a value for each row separately. Window functions can only be calculated once the entire table is read.

You can use window functions to perform operations such as:

• Comparing an individual number value in a row with the average, maximum, or minimum within the column.

• Calculating the rank of an individual value, either within the column or within the entire table.

Window functions do not change the number of records in the table but can perform similar tasks as aggregation functions or relational functions and range functions.

使用每个函数的下拉列表可查看每个函数的简短描述和语法。单击语法描述中的函数名称可了解更多信息。

Window

The Window function performs calculations from multiple rows, producing a value for each row separately.

window(main_expr, [partition1, partition2, ...], [sort_type, [sort_expr],[filter_expr], [start_expr, end_expr]])

WRank

The WRank function performs ranking calculations inside Window.

wrank([mode[, fmt]])