Agenten Generally, it’s best practice to put unique constraints on a table to prevent duplicate rows. However, you may find yourself working with a database where duplicate rows have been created through human error, a bug in your application, or uncleaned data from external sources. This t...
[cc lang=”sql”] SELECT FirstName ,DuplicateCount = COUNT(1) FROM SalesLT.Customer GROUP BY FirstName HAVING COUNT(1) > 1 — more than one value ORDER BY COUNT(1) DESC — sort by most duplicates [/cc] Duplicate FirstNames in Customers Table ...
Ajax request SQL Server alert after kendo grid load alert box after response.end() Alert on C# in web Method Static Method align a panel to the center Align image at center in pdfpCell using iTextSharp. Align Textbox for input with Gridview grid align textbox in a cell of a table to ...
Finding Duplicates with DISTINCT and HAVING Finding last occurrence of a space in a string Finding spaces in a string Finding the second space in a string First 3 columns data of a table without specifying the column names - SQL Server First and Last day of previous month from getdate() ...
In my experience, it is more efficient to use aduplicate file remover app for PCin order to find and remove duplicate files on Windows 11 and Windows 10. Here is why: Efficiency: Third-party tools are specifically designed to find and remove duplicates, ...
Here is the situation. I have column A which shows account numbers. Column B shows what group that account belongs to (groups 1&2). I am trying to find the duplicates that belong to both groups. For example, I want to find the duplicate accounts where one of the accounts belongs to ...
create_table :users do |t| t.string :email, null: false, index: { unique: true } t.string :password_digest, null: false # ... other fields ... end In app/models/user.rb, enable: 1 2 3 4 class User < ApplicationRecord has_secure_password # ... end This gives you user.aut...
(username, last_login);Query OK, 0 rows affected (7.88 sec)Records: 0 Duplicates: 0 Warnings: 0 mysql> EXPLAIN SELECT * FROM user WHERE username = "admin1" ORDER BY last_login DESC\G*** 1. row *** id: 1 select_type: SIMPLE table: user partitions: NULL type: refpossiblekeys:...
Ah, good question. What if the table isn’t InnoDB, or what if someone locked it withLOCK TABLES, and it doesn’t show up in the output ofSHOW ENGINE INNODB STATUS? As far as I know, you’re helpless. I don’t know how to get any information on who’s locking the table then....
in set, 1 warning (0.00 sec) Now I drop the index idx_DataDate : mysql> alter table ms_transferhourse drop index idx_DataDate ; Query OK, 0 rows affected (7.29 sec) Records: 0 Duplicates: 0 Warnings: 0 And then run this sql explain again: mysql> desc select count(*) from ms_...