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How to tell when UITableView has completed ReloadData?
I am trying to scroll to the bottom of a UITableView after it is done performing [self.tableView reloadData]
19 Answers
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Difference Between Schema / Database in MySQL
...racle Database product, a schema represents only a part of a database: the tables and other objects owned by a single user.
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how can I Update top 100 records in sql server
I want to update the top 100 records in SQL Server. I have a table T1 with fields F1 and F2 . T1 has 200 records. I want to update the F1 field in the top 100 records. How can I update based on TOP 100 in SQL Server?
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MySQL offset infinite rows
I would like to construct a query that displays all the results in a table, but is offset by 5 from the start of the table. As far as I can tell, MySQL's LIMIT requires a limit as well as an offset. Is there any way to do this?
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LINQ to SQL Left Outer Join
..."left" row in a left-outer-join will match 0-n "right" rows (in the second table), where-as yours matches only 0-1. To do a left outer join, you need SelectMany and DefaultIfEmpty, for example:
var query = from c in db.Customers
join o in db.Orders
on c.CustomerID equals o...
clear table jquery
I have an HTML table filled with a number of rows.
10 Answers
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Relative frequencies / proportions with dplyr
...our depending on the version of dplyr:
dplyr 0.7.1: returns an ungrouped table: you need to group again by am
dplyr < 0.7.1: returns a grouped table, so no need to group again, although you might want to ungroup() for later manipulations
dplyr 0.7.1
mtcars %>%
count(am, gear) %>%
g...
generate days from date range
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This solution uses no loops, procedures, or temp tables. The subquery generates dates for the last 10,000 days, and could be extended to go as far back or forward as you wish.
select a.Date
from (
select curdate() - INTERVAL (a.a + (10 * b.a) + (100 * c.a) + (1000 * d...
B-Tree vs Hash Table
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You can only access elements by their primary key in a hashtable.
This is faster than with a tree algorithm (O(1) instead of log(n)), but you cannot select ranges (everything in between x and y).
Tree algorithms support this in Log(n) whereas hash indexes can result in a full table s...
When to use “ON UPDATE CASCADE”
... ON UPDATE CASCADE would allow you to change the primary key value and any tables that have foreign key references to the value will be changed accordingly.
In reference to #4, if you change the child ID to something that doesn't exist in the parent table (and you have referential integrity), you s...