大约有 40,000 项符合查询结果（耗时：0.0553秒） [XML]
Replace all 0 values to NA
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What would the equivalent syntax be for a data.table object?
– itpetersen
Dec 7 '14 at 5:33
6
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How to import load a .sql or .csv file into SQLite?
...'m using SQLite3 API). I've only found documentation for importing/loading tables, not entire databases. Right now, when I type:
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Order data frame rows according to vector with specific order
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Does anyone know a data.table version of this?
– Reilstein
Sep 23 '16 at 17:50
2
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SQL Joins Vs SQL Subqueries (Performance)?
...ies with Semijoin Transformations
Rewriting Subqueries as Joins
I have a table with 50000 elements, the result i was looking for was 739 elements.
My query at first was this:
SELECT p.id,
p.fixedId,
p.azienda_id,
p.categoria_id,
p.linea,
p.tipo,
p.nome
FROM prodotto p
WH...
Simple way to copy or clone a DataRow?
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You can use ImportRow method to copy Row from DataTable to DataTable with the same schema:
var row = SourceTable.Rows[RowNum];
DestinationTable.ImportRow(row);
Update:
With your new Edit, I believe:
var desRow = dataTable.NewRow();
var sourceRow = dataTable.Rows[rowNum]...
FIND_IN_SET() vs IN()
I have 2 tables in my database. One is for orders, and one is for companies.
6 Answers
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Client-server synchronization pattern / algorithm?
...g every change (insert, update or delete) from any device into a "history" table. So if, for example, someone changes their phone number in the "contact" table, the system will edit the contact.phone field, and also add a history record with action=update, table=contact, field=phone, record=[contact...
Change SVN repository URL
...your working copy. Just open the database (e.g. in SQLite Browser), browse table REPOSITORY, and change the root and uuid column values to the new ones. You can find the UUID of the new repo by issuing svn info NEW_SERVER.
Again, treat this as a last resort method.
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How do I delete a fixed number of rows with sorting in PostgreSQL?
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You could try using the ctid:
DELETE FROM logtable
WHERE ctid IN (
SELECT ctid
FROM logtable
ORDER BY timestamp
LIMIT 10
)
The ctid is:
The physical location of the row version within its table. Note that although the ctid can be used to locate the...
What requests do browsers' “F5” and “Ctrl + F5” refreshes generate?
...trol by adding "Pragma: No-cache" when you pressed CTRL-F5.
Edit: Updated table
The table below is updated with information on what will happen when the browser's refresh-button is clicked (after a request by Joel Coehoorn), and the "max-age=0" Cache-control-header.
Updated table, 27 September 20...