参考官方文档https://support.microsoft.com/zh-cn/help/139444/how-to-remove-duplicate-rows-from-a-table-in-sql-serverlink 原文摘录 需要检查是否是除了id列之外的整行重复,请对比所有列之后,选择需要保留的行 只有几组重复的 PK 值(手动删除) 在该示例中,我们将使用下表,它具有重复的 PK 值。 在该表...
SELECTDISTINCT*INTOduplicate_tableFROMoriginal_tableGROUPBYkey_valueHAVINGCOUNT(key_value) >1DELETEoriginal_tableWHEREkey_valueIN(SELECTkey_valueFROMduplicate_table)INSERToriginal_tableSELECT*FROMduplicate_tableDROPTABLEduplicate_table 此脚本按给定顺序执行以下操作: ...
Scenario 2.a: Delete Duplicate rows but keep one using CTE We need to use the technique of Self Join initially to check for duplicate records containing different custid but same passport number. select distinct a.* from customers2 a join customers2 b on a.custid <> b.custid and a.CustN...
ROW_NUMBER WF enumerates the rows. We can also use it to remove duplicate records with it. Or to take a random sample. As the name suggests WF can calculate statistics on a given window: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 sum(sales)OVER(PARTITIONBYCustomerIDBYtsROWSBETWEEN...
from films f ) select * from film_counts where ct > 1 With a list of the duplicates in hand, it's time for the next step! How to Delete the Duplicate Rows Delete key1by Büşra ÖZCOŞKUNCC BY-SA 4.0 Now you've identified the copies, you often want to delete the extra rows...
SELECT b.BookNumber, b.Title, b.Stock FROM dbo.Book b The output is: Delete the Data based on a Different Condition Assume that we need to remove out of stock books to keep more accurate information in the database. To do this, we should look for those rows with the Stock is 0. ...
开始我们拿sql到数据库查询平台查库执行计划,无奈这个平台有bug,delete语句无法查看,所以我们改成select,“应该”是一样。这个“应该”加了双引号,导致我们走了一点弯路。 EXPLAINSELECT*fromt_table_1wheretask_idin(selectidfromt_table_2whereuid=1)
Although individual columns in a result set may contain duplicate values, an entire row must be an exact duplicate of another for it to be removed byDISTINCT. In this case, every value in thenamecolumn is unique soDISTINCTdoesn’t remove any rows when that column is specified in theSELECT...
B. Use SELECT with column headings and calculations The following examples return all rows from theProducttable. The first example returns total sales and the discounts for each product. In the second example, the total revenue is calculated for each product. ...
'ROWS', 'ROW_COUNT', 'ROW_FORMAT', 'RTREE', 'SAVEPOINT', 'SCHEDULE', 'SCHEMA', 'SCHEMAS', 'SCHEMA_NAME', 'SECOND', 'SECOND_MICROSECOND', 'SECURITY', 'SELECT', 'SENSITIVE', 'SEPARATOR', 'SERIAL', 'SERIALIZABLE', 'SERVER', 'SESSION', 'SET', 'SHARE', 'SHOW', 'SHUTDOWN', '...