sql - MySQL: Code To Compare 2 Tables, Then If row is the same update Master Date -

-

I have two tables, they are called Master and NewData, the schema on both tables is exactly the same and there are field names in it: CODE, SERIAL, model, VALIDATED_DATE.

I want to see if the value of the CODE field is present in the NEWDATA table and the master table if they are in both tables, then I want to update the Master of Table on VALIDATED_DATE.

I have lots of records so I'm curious what's the fastest way to do this?

Thank you! 

  update master m also includes n.code = M.code on newdata n .validated_date = now ()

The code column should be indexed for this task to work efficiently. Given that it should be fast, which is much faster than the other methods mentioned above (unless you are running mysql 5.4, the correlated subquery execution of mysql is basically completely unused).


Comments

Post a Comment

Popular posts from this blog

asp.net - Javascript/DOM Why is does my form not support submit()? -

-
This is my first time working with asp.net and javascript, so I do not know very good web resources, or Much about javascript debugging I have to find out that on line oFormObject.submit (); Microsoft JScript Runtime Error: Object does not support this property or method I am using the link to work as a button because I am terrible in aesthetics and I think That link will look more professional than a table of 50 buttons. I have read that this solution can cause problems with browsers due to pre-rendering of my links and many additional traffic and problems, but CSS gives me a button like a link, which has issues of alignment and difference seemed to. & lt ;! DOCTYPE HTML PUBLIC "- // W3C // DTD HTML 4.01 // N" "http://www.w3.org/TR/html4/strict.dtd"> & Lt; Html xmlns = "http://www.w3.org/1999/xhtml" & gt; & Lt; Head & gt; & Lt; Link rel = "stylesheet" type = "text / css" href = "defect differen
Read more

sockets - Delphi: TTcpServer, connection reset when reading -

-
I am trying to implement one for Delphi, but there are some problems with communication. Fitnesse will start my process, and give me a portmember as a command line argument. Then I should make a socket on the port number given to me, and fitness will connect to that port I am using a TCPCP server for the job: < Pre> TcpServer1.LocalPort: = ParamStr (ParamCount); TcpServer1 Active: = true; On OnEXEPT () -Event, I send the protocol version to use as specified in the protocol. Process TForm1.TcpServer1Accept (From: TOBject; ClientSocket: TCustomIpClient); Var s: ansistring; Start clientSocket. Syndrome ('slim - v 0.0', # 10); SetLength (S, 6); ClientSketts Receavebook (S, 6); End; When I call ReceiveBuf (), the process ends, and fitness throws an exception: java.net.SocketException: connection Reset I have seen what sent and received. It shows that my code sends the protocol version, fitness sends back a message, and when I try to get this message
Read more

javascript - Classic ASP "ExecuteGlobal" statement acting differently on two servers -

-
I have a strange problem that I really do not know. In addition to developing a new ASP.NET site, I have to support the old "classic ASP" site. It is written in VBScript with a batch of JavaScript functions. Many of the JavaScript functions include 'files' Everything is fine on our production system (which security is controlled by another group - this is a military installation) Debugging them once did not work I). However, I have a fix for a vague bug that needs to be fully tested and some functions do not run under the "local" copy of the website that runs on my PC. For the record, I am running IIS 5.1 on XP. The problem is that some Javascript functions are running "OK" on the production server, but when they use it as a server, they are not defined on my PC what is happening that last Programmer, for some reason, has decided to put some functions in a series of files, which according to the observations, imitate the "need_once
Read more