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How to request a random row in SQL?
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See this post: SQL to Select a random row from a database table. It goes through methods for doing this in MySQL, PostgreSQL, Microsoft SQL Server, IBM DB2 and Oracle (the following is copied from that link):
Select a random row with MySQL:
SELECT column FROM table
ORDER BY RAND()...
How to make a JTable non-editable
How to make a JTable non-editable? I don't want my users to be able to edit the values in cells by double-clicking them.
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ActiveRecord: size vs count
...e way to go if you are using the data.
Example: Summary of a fully loaded table, titles of displayed data, etc.
size
It checks if the data was loaded (i.e. already in rails) if so, then just count it, otherwise it calls count. (plus the pitfalls, already mentioned in other entries).
def size
l...
Can you do this HTML layout without using tables?
... are available to you to do the job quickly and correctly.
In this case a table worked perfectly.
I personally would have used a table for this.
I think nested tables should be avoided, things can get messy.
share
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How can I create a copy of an Oracle table without copying the data?
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Just use a where clause that won't select any rows:
create table xyz_new as select * from xyz where 1=0;
Limitations
The following things will not be copied to the new table:
sequences
triggers
indexes
some constraints may not be copied
materialized view logs
This also does no...
Open-sided Android stroke?
...fill_parent"
android:layout_height="0dp"
android:layout_below="@id/table_options"
android:layout_above="@id/exit_bar"/>
Which fills the gap between table_options and exit_bar with a background and just before exit_bar prints a 1dp line. This did the trick for me, I hope it helps som...
COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better? [duplicate]
...OUNT(*), and stick with it consistently, and if your database allows COUNT(tableHere) or COUNT(tableHere.*), use that.
In short, don't use COUNT(1) for anything. It's a one-trick pony, which rarely does what you want, and in those rare cases is equivalent to count(*)
Use count(*) for counting
U...
Physical vs. logical / soft delete of database record?
...and you don't have to worry about cascading a delete through various other tables in the database that reference the row you are deleting. Disadvantage is that you have to code any reporting/display methods to take the flag into account.
As far as if it is a common practice - I would say yes, but ...
How do I find which transaction is causing a “Waiting for table metadata lock” state?
I am trying to perform some DDL on a table and SHOW PROCESSLIST results in a " Waiting for table metadata lock " message.
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Why doesn't GCC optimize a*a*a*a*a*a to (a*a*a)*(a*a*a)?
...eatly slows down the performance. (In contrast, Intel C++ Compiler , executable icc , will eliminate the library call for pow(a,6) .)
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