sql-server - 如何检测 SQL Server 表中的重复行？

Question

在 10 列/50K 行表中检测重复项的最有效方法是什么？我正在使用 MSSQL 8.0

Answer 1

展示其他人所描述的示例:

SELECT
    Col1, -- All of the columns you want to dedupe on
    Col2, -- which is not neccesarily all of the columns
    Col3, -- in the table
    Col4,
    Col5,
    Col6,
    Col7,
    Col8,
    Col9,
    Col10
FROM
    MyTable
GROUP BY
    Col1,
    Col2,
    Col3,
    Col4,
    Col5,
    Col6,
    Col7,
    Col8,
    Col9,
    Col10
HAVING
    COUNT(*) > 1