sql - PostgreSQL if temporary table is dropped query is empty -


I am working on a simple homework assignment where I have to get some data which complies with some parameters and then The second goes to the query on the query that was selected in the previous query.

I am creating a temporary table and generating it with the results of the first query and then run another query on the table. Then I leave the table.

Here's the problem: If I leave the table, the second question is empty because the result is abandoned. I do not understand this. I do not use a temporary table for selection, only for data validation. And even if the table is dropped at the end of the query query, the query is empty. If I do not leave the table, then it works fine but if I run the query again, it says that the table is present. What am I doing wrong here. Here's the code: 

  Select the temporary table TMP from the edge where the weight> 100; Choose Graph from TMP, Graph Grapho = tmp.no and gesm (graph. Gno) & gt; = Select all from the graph (SELECT gsum (graph.gno) gname, gsum (graph.gno););    
 
 
 Temporary tables are unique for each session, they are created in a special temporary schema. In only one session and only till the end of the session (unless previously dropped) appear.  
 This is the first schema in the temporary schema  interactively  (schema  pg_catalog  after system), so it is effectively the other table of the same name Hides. 
 
 
 Existing permanent tables with the same name are not visible to the current session, whereas a temporary table is present, unless they are referred to by the schema qualified name. 
 
 
 Once you leave the temporary table, the next table becomes visible again with the same name in the  search_path  and its current < There is no matching value in the code> gno  column, so the result is empty. 
 
 It should be because, if such a table does not exist, you will not get the  empty  result for the next attempt, but will receive an error message 
 
 In addition, your second query should be: 
 
  SELECT gname, gsum (graph.gno) Use the Tmp JOIN article (GNO) WHERE gsum (graph.gno) = (SELECT max (From the graph.gno) graph);  
 
 Clear  JOIN  with syntax and simplified  WHERE  condition. Assume  gsum ()  is a plain function,  not  a composite function.
-

Comments

Post a Comment

Popular posts from this blog

sqlite3 - UPDATE a table from the SELECT of another one -

I have the first table article where some data is missing. In the table, articles_tmp I have a part of the missing data. So I want to update the articles. Where the path path is data in articles_tmp.path where the path is not zero . With SQLite , it does not work: update article SET path = (SELECT at.path FROM Articles_tmp as AS, WHERE at.article_id = a.id and a.asp, the text is in the form and not on. It has been transmitted) where the path is null MS Access Along with, it works fine: Update Articles Join the Inner Articles at articles_tmp articles.id = articles_tmp.id SETP articles.path = articles_tmp.path Can anyone help? Sin CE SQL Server Syntax, which I provided, was not working, here this solution With whom I have come. A little modification of your original query, but with my "correlation" suggestion added. There is a SQL Bella for this: Here is the code: update article SET path = (SELECT path from articles_tmp AS T WHERE t.id
Read more

c# - Showing a SelectedItem's Property -

So I have enabled a rightclick option for my DataGrid. I want to display the only chosen property but it is not behaving like what I would like it to display my name and additional. Public category Paymentinfo {public int PaymentNo {get; Set; } Public string date {get; Set; } Public Double Pay {get; Set; } Public Double Principle {get; Set; } Public Double Interest {get; Set; } Public Double Balance {Received; Set; }} Private Zero MenuItem_OnClick (Object Sender, RoutedEventArgs e) {MessageBox.Show (AmortGrid.SelectedItem.ToString ()); } I'm trying to apply it without using a View Module! If I place a breakpoint where the messagebox and the recipient place it on selected ITEM, then this property will display the payment. A date-payment-principle-interest-balance is the only value that needs payment. Was hoping that it would be something like this MessageBox.Show (AmortGrid.SelectedItem.PaymentNo.ToString ()); When you call ToString () So you get the class typ
Read more

javascript - Render HTML after each iteration in loop -

I'm trying to gradually increase the font size of text on a web page. The code works in my place, although the new HTML / CSS does not render after every iteration of the loop and when all this is done, then display only the text of 100 px size. To see the text as if it is slowly zooming, I need to do this JavaScript is down because it is being used from a different file here is what I have ... < Pre> & lt; P class = "game-title" style = "font-size: 50px" & gt; Test & lt; / P & gt; Function sleep (milliseconds) {var start = new date (). GetTime (); For (var i = 0; i & lt; 1e7; i ++) {if ((new date). GetTime () - start) & gt; Milliseconds {break; CSS ('font-size', 'parseInt ($ (' game-title '). CSS (' font-size ')) + 1 + "pixels"); } While (parasont ($ ('# text'). Css ('font-size')) & lt; = 100) {sleep (1000); IncreaseSize (); Using CSS: Use of jQuery (sample):
Read more