大约有 47,000 项符合查询结果（耗时：0.0209秒） [XML]
PostgreSQL - max number of parameters in “IN” clause?
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explain select * from test where id in (values (1), (2));
QUERY PLAN
Seq Scan on test (cost=0.00..1.38 rows=2 width=208)
Filter: (id = ANY ('{1,2}'::bigint[]))
But if try 2nd query:
explain select * from test where id = an...
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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Getting a 404 from WMSvc via MSDeploy.exe
...el > Programs and Features. Right-click "Microsoft Web Deploy 3.5" and select "Change". From the installer select "Change" and "IIS Deployment Handler" was available as an option (was disabled at first. Also "Configure for Non-Administrator Deployments" and "Management Service Delegation UI" w...
MySQL offset infinite rows
...er. This statement
retrieves all rows from the 96th row
to the last:
SELECT * FROM tbl LIMIT 95, 18446744073709551615;
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Anyway to prevent the Blue highlighting of elements in Chrome when clicking quickly?
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In addition to the link provided by Floremin, which clears text selection using JavaScript to "clear" the selection, you can also use pure CSS to accomplish this. The CSS is here...
.noSelect {
-webkit-touch-callout: none;
-webkit-user-select: none;
-khtml-user-select: none;
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How can I disable the UITableView selection?
When you tap a row in a UITableView , the row is highlighted and selected. Is it possible to disable this so tapping a row does nothing?
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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...
Difference between two dates in MySQL
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SELECT TIMEDIFF('2007-12-31 10:02:00','2007-12-30 12:01:01');
-- result: 22:00:59, the difference in HH:MM:SS format
SELECT TIMESTAMPDIFF(SECOND,'2007-12-30 12:01:01','2007-12-31 10:02:00');
-- result: 79259 the differenc...
Using DISTINCT and COUNT together in a MySQL Query
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use
SELECT COUNT(DISTINCT productId) from table_name WHERE keyword='$keyword'
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Only read selected columns
...from the data.table-package:
You can specify the desired columns with the select parameter from fread from the data.table package. You can specify the columns with a vector of column names or column numbers.
For the example dataset:
library(data.table)
dat <- fread("data.txt", select = c("Year...