大约有 47,000 项符合查询结果（耗时：0.0413秒） [XML]
Rank function in MySQL
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One option is to use a ranking variable, such as the following:
SELECT first_name,
age,
gender,
@curRank := @curRank + 1 AS rank
FROM person p, (SELECT @curRank := 0) r
ORDER BY age;
The (SELECT @curRank := 0) part allows the variable initializatio...
Rename package in Android Studio
...n:
In your Project pane, click on the little gear icon ( )
Uncheck / De-select the Compact Empty Middle Packages option
Your package directory will now be broken up in individual directories
Individually select each directory you want to rename, and:
Right-click it
Select Refactor
Click o...
mysql :: insert into table, data from another table?
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INSERT INTO action_2_members (campaign_id, mobile, vote, vote_date)
SELECT campaign_id, from_number, received_msg, date_received
FROM `received_txts`
WHERE `campaign_id` = '8'
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How to count instances of character in SQL Column
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In SQL Server:
SELECT LEN(REPLACE(myColumn, 'N', ''))
FROM ...
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SQL statement to get column type
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Using SQL Server:
SELECT DATA_TYPE
FROM INFORMATION_SCHEMA.COLUMNS
WHERE
TABLE_NAME = 'yourTableName' AND
COLUMN_NAME = 'yourColumnName'
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LINQ - Full Outer Join
...rst.ID equals last.ID into temp
from last in temp.DefaultIfEmpty()
select new
{
first.ID,
FirstName = first.Name,
LastName = last?.Name,
};
var rightOuterJoin =
from last in lastNames
join first in firstNames on last.ID equals first.ID into temp
fr...
Extract a dplyr tbl column as a vector
...2 3.62 3.54 4.11
A nice way to do this in v0.2 of dplyr:
iris2 %>% select(Species) %>% collect %>% .[[5]]
Or if you prefer:
iris2 %>% select(Species) %>% collect %>% .[["Species"]]
Or if your table isn't too big, simply...
iris2 %>% collect %>% .[["Species"]]
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SQLite - UPSERT *not* INSERT or REPLACE
... (id, role, name)
VALUES ( 1,
'code monkey',
(SELECT name FROM Employee WHERE id = 1)
);
This will update 2 of the columns.
When ID=1 exists, the ROLE will be unaffected.
When ID=1 does not exist, the role will be set to 'Benchwarmer' instead of the default v...
Hide options in a select list using jQuery
...ave an object with key/value pairs of options I want to hide/remove from a select list.
Neither of the following option selectors work. What am I missing?
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✔ Checkmark selected row in UITableViewCell
...pment newbie. I want to add a checkmark to my UITableViewCell when it is selected. The checkmark should be removed when another row is selected. How would I do this?
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