Six years after you posted this video and it is still helping people. Thank you for taking the time to create this video. I have been struggling with this concept and this finally allowed me to pull exactly what I needed.
I have a doubt. I have table with two fields, one field is array in table 1 uID | Contact 2 | 1221,1223 3 | 1123 Now value of 1221 and 1223 are in table Two. I want a query to join table 1 and table 2 using array of field2
You said that the old way is less efficient (slower) than using the JOIN function. Do you have a comment as to why this is? And also, the theoretical and actual difference in performance? Btw, great videos.
Kson Whoops. explain shows that the query evaluation plan is identical for the two. I stand corrected; they look to be equivalent. And a quick benchmarking shows equivalent performance. I guess I assumed since the WHERE join is older (ANSI-89) it is inferior performance-wise. Not so, apparently. Sorry about that. I do think, however, that the JOIN syntax improves readability/maintainability because it makes joining distinct from filtering. Easier to keep things consistent inner vs outer join too. Thanks for asking.
Brian Finnegan Thank you. That clarified it for me :) I realise it has been some time since you released these videos, but if you ever make another one, a video about outer and inner joins would be great!
KobleOza Good idea. I've been meaning to do that one for a while and now have added an inner vs. outer video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-RpWcN7GosfE.html
You can use the up and down arrows to scroll through all of your previous statements. You can also literally copy and paste in PuTTY (and, presumably other SSH clients). In PuTTY, to copy just click and drag your mouse to highlight what you want copied. It is automatically added to the clipboard. Then to paste, just right click.
Please I have a few questions which I need help with. For these I have the tables ready but I am not sure if my queries are right. All the tables that I need are in section 1 which are done and completed. But for the queries from these tables are so confusing. I want to show you what I have done could you please show me if they are right . Please reply me if you can help me. I will send you all the queries I have done in the morning if you are ready to help me. Thank you God bless you. Kind regards Arslan
