大约有 47,000 项符合查询结果（耗时：0.0257秒） [XML]
Unable to run app in Simulator: Xcode beta 6 iOS 8
...r dialog shows up, you still would have access to the iOS Simulator's menu
Select Hardware > Device > Manage Devices
Click on the little + sign at the bottom
Add (if missing) all the devices that you want, or delete and recreate the ones malfunctioning.
If anyone of the simulator is not workin...
SQL Server Insert if not exists
..., Assunto, Data)
VALUES (@_DE, @_ASSUNTO, @_DATA)
WHERE NOT EXISTS ( SELECT * FROM EmailsRecebidos
WHERE De = @_DE
AND Assunto = @_ASSUNTO
AND Data = @_DATA);
END
replace with
BEGIN
IF NOT EXISTS (SELECT * FROM EmailsRecebidos
...
updating table rows in postgres using subquery
...ery.customer,
address=subquery.address,
partn=subquery.partn
FROM (SELECT address_id, customer, address, partn
FROM /* big hairy SQL */ ...) AS subquery
WHERE dummy.address_id=subquery.address_id;
This syntax is not standard SQL, but it is much more convenient for this type of query...
ComboBox: Adding Text and Value to an Item (no Binding Source)
...ext1";
item.Value = 12;
comboBox1.Items.Add(item);
comboBox1.SelectedIndex = 0;
MessageBox.Show((comboBox1.SelectedItem as ComboboxItem).Value.ToString());
}
share
|
improve this...
Mysql: Select rows from a table that are not in another
How to select all rows in one table that do not appear on another?
8 Answers
8
...
How do I use Linq to obtain a unique list of properties from a list of objects?
...
IEnumerable<int> ids = list.Select(x=>x.ID).Distinct();
share
|
improve this answer
|
follow
|
...
Possible to perform cross-database queries with PostgreSQL?
... executes a query in a remote database
dblink executes a query (usually a SELECT, but it can be any SQL
statement that returns rows) in a remote database.
When two text arguments are given, the first one is first looked up as
a persistent connection's name; if found, the command is executed on
that...
How to export table as CSV with headings on Postgresql?
...
@arilwan psql -c "\COPY (SELECT * FROM mytable) TO STDOUT" > mytable.csv
– Juha Palomäki
Jun 6 '19 at 16:00
...
How to do a FULL OUTER JOIN in MySQL?
...MPLE transcribed from this SO question you have:
with two tables t1, t2:
SELECT * FROM t1
LEFT JOIN t2 ON t1.id = t2.id
UNION
SELECT * FROM t1
RIGHT JOIN t2 ON t1.id = t2.id
The query above works for special cases where a FULL OUTER JOIN operation would not produce any duplicate rows. The quer...
Count number of records returned by group by
...
You can do both in one query using the OVER clause on another COUNT
select
count(*) RecordsPerGroup,
COUNT(*) OVER () AS TotalRecords
from temptable
group by column_1, column_2, column_3, column_4
share
...