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mysql - how many columns is too many?
...every column to be returned by every query is perfectly normal; that's why SELECT statement lets you explicitly name the columns you need.
As a general rule, your table structure should reflect your domain model; if you really do have 70 (100, what have you) attributes that belong to the same entit...
Entity Framework: There is already an open DataReader associated with this Command
...al commands executed on single connection (or single command with multiple selects) while next DataReader is executed before first one has completed the reading. The only way to avoid the exception is to allow multiple nested DataReaders = turn on MultipleActiveResultSets. Another scenario when this...
Rails Object to hash
...
Works with joins and select, Person.joins(:address).select("addresses.street, persons.name").find_by_id(id).attributes, will return { street: "", name: "" }
– fangxing
Jun 15 '17 at 2:29
...
jQuery/Javascript function to clear all the fields of a form [duplicate]
...switch(this.type) {
case 'password':
case 'select-multiple':
case 'select-one':
case 'text':
case 'textarea':
$(this).val('');
break;
case 'checkbox':
...
SQLite - How do you join tables from different databases?
...s with keyword
.databases
Then you should be able to do the following.
select
*
from
db1.SomeTable a
inner join
db2.SomeTable b on b.SomeColumn = a.SomeColumn;
Note that "[t]he database names main and temp are reserved for the primary database and database to hold temporary tables a...
How to perform .Max() on a property of all objects in a collection and return the object with maximu
...c T MaxObject<T,U>(this IEnumerable<T> source, Func<T,U> selector)
where U : IComparable<U> {
if (source == null) throw new ArgumentNullException("source");
bool first = true;
T maxObj = default(T);
U maxKey = default(U);
foreach (var ...
How can I disable ReSharper in Visual Studio and enable it again?
...nd to Ctrl alt A. That might be because Re# has bound the Ctrl W to Extend selection
– Default
Feb 21 '13 at 9:52
...
Is there a way to rename an Xcode 4 scheme?
... hit "Manage Schemes". Once you do so, you'll have a window like this:
Select the scheme you want to change, and hit Return.
Now the scheme name will be editable, and you can change it to your hearts desire. Then hit Return again to save it.
...
More elegant “ps aux | grep -v grep”
...
@kxsong: | grep '[t]erminal' selects any line containing the word 'terminal' without putting the word 'terminal' into the process list. What are you trying to achieve with | grep '[r]oot' and how is it not working? There is likely to be a better solution...
Should I commit or rollback a read transaction?
... I create a temp table, populate it with ids, join it with a data table to select the data that goes with the ids, then delete the temp table. I'm really just reading data, and I don't care what happens to the temp table, since it's temporary... but from a performance perspective, would it be more ...