I am doing this, to have table 1 and table 2 side by side.
masterTable.addCell(table1);
masterTable.addCell(table2);
But here is the problem. If one of the tables has more rows than the other table. The table with less rows will grow the last row to get to same height as the other.
How to avoid this?
Related
I have imported a large database in anylogic, having various columns. The rows can be selected using unique primary key in database table. Similarly, how can i move through columns using integer indexes?
The attached picture shows the selection query of encircled cell, to get to other cell i need to change columns again in query which is surely not efficient 1.
So my following table is like this:
Tower_ID|...|Insulator_ID_01|Insulator_ID_02|...|Insulator_ID_12|
Tower_01|...|01_Unique_ID_01|01_Unique_ID_02|...|01_Unique_ID_12|
Tower_02|...|02_Unique_ID_01|02_Unique_ID_02|...|02_Unique_ID_12|
Then the idea is to have a single table for every insulator that belongs to towers in this specific line (towers in this line is the table). But the only way I know how is to have a table for each column of insulators. Is it possible to create a single table with relationships which would store Insulator_ID_01 to Insulator_ID_12 in a column before going into the next row of the and doing the same?
So I have a table where I'm trying to get rid of some rows.
All these rows contain a letter where they should only contain a numeric value.
Example:Columns
So I pretty much want to copy the column grade_percent of column 1 to 'class_rank' of column 2 and then delete column 1.
The thing is that I have about 9k rows and there are different marking_period_ids
I was thinking of doing something like
UPDATE table SET class_rank=(SELECT exam from table WHERE marking_period_id)
but that's where I get lost as I have no idea how to make this repetitive straight from a postgresql query
If I had a table of products and another table of manufacturers, and I wanted that table to have a count of products, is there a way in postgres to say "this column equals the number of rows in this other table that meet this condition"?
EDIT: I mean to say that the column value will be automatically calculated. So if I have a table with a column for the number of products that are red, I want this column to consistently equal the number of rows that result from doing select * from products where color='red';, without having to consistently perform that query myself.
You should not store calculated values in an operational database. If it's data warehouse, go ahead.
You can use a view to do the calculation for you.
http://sqlfiddle.com/#!15/0b744/1
You can use a materialized view to increase performance, and refresh it with a trigger on products table.
We store billions of rows in an infobright table which currently has about 45 columns. We want to add 50 more columns to it. Will adding these columns bring down the performance of reads? Is creating a new table for these columns a better option? Or, since infobright is a column oriented database additions of 50 extra columns not matter much?
Thanks!
I think "adding these columns" will not "bring down the performance of reads" that do not use the added columns.
I think "creating a new table for these columns" is not "a better option".
Since "infobright is a column oriented database additions of 50 extra columns" should have no effect on the performance of queries that do not use the added columns.
The maximum number of columns for Infobrigh6t tables is 4096. However, that is if they are only TINYINT columns. I would suggest that you do not use more than 1000 columns. The key though is ensuring that in your SQL query that you do not do a SELECT * FROM. You should SELECT CustomerID, CustomerName FROM instead for ONLY those columns necessary to resolve your needs.