大约有 40,000 项符合查询结果（耗时：0.0223秒） [XML]
How to delete the top 1000 rows from a table using Sql Server 2008?
...
The code you tried is in fact two statements. A DELETE followed by a SELECT.
You don't define TOP as ordered by what.
For a specific ordering criteria deleting from a CTE or similar table expression is the most efficient way.
;WITH CTE AS
(
SELECT TOP 1000 *
FROM [mytab]
ORDER BY a1
)
DELET...
Delete all Duplicate Rows except for One in MySQL? [duplicate]
...te.
INSERT INTO tempTableName(cellId,attributeId,entityRowId,value)
SELECT DISTINCT cellId,attributeId,entityRowId,value
FROM tableName;
share
|
improve this answer
|
...
Is there a format code shortcut for Visual Studio?
...Ctrl+E, Ctrl+D to format the entire document.
Ctrl+E, Ctrl+F to format the selection.
You can change these in menu Tools → Options → Environment → Keyboard (either by selecting a different "keyboard mapping scheme", or binding individual keys to the commands "Edit.FormatDocument" and "Edit.For...
Datatype for storing ip address in SQL Server
...VARCHAR(15)) RETURNS BINARY(4)
AS
BEGIN
DECLARE @bin AS BINARY(4)
SELECT @bin = CAST( CAST( PARSENAME( @ip, 4 ) AS INTEGER) AS BINARY(1))
+ CAST( CAST( PARSENAME( @ip, 3 ) AS INTEGER) AS BINARY(1))
+ CAST( CAST( PARSENAME( @ip, 2 ) AS INTEGER) AS BINARY(1))
...
MySQL SELECT WHERE datetime matches day (and not necessarily time)
...
NEVER EVER use a selector like DATE(datecolumns) = '2012-12-24' - it is a performance killer:
it will calculate DATE() for all rows, including those, that don't match
it will make it impossible to use an index for the query
It is much fas...
How to convert int to char with leading zeros?
...
Try this: select right('00000' + cast(Your_Field as varchar(5)), 5)
It will get the result in 5 digits, ex: 00001,...., 01234
share
|
...
Counting DISTINCT over multiple columns
... function turns the ints into varchars to make the distinct more reliable
SELECT COUNT(DISTINCT (CHECKSUM(DocumentId,DocumentSessionId)) + CHECKSUM(REVERSE(DocumentId),REVERSE(DocumentSessionId)) )
FROM DocumentOutPutItems
...
Recommended SQL database design for tags or tagging [closed]
...ries which you will do: Output all Tags for one Item, draw a Tag-Cloud and select all items for one Tag Title.
All Tags for one Item:
3-Table:
SELECT Tag.Title
FROM Tag
JOIN ItemTag ON Tag.TagID = ItemTag.TagID
WHERE ItemTag.ItemID = :id
2-Table:
SELECT Tag.Title
FROM Tag
WHERE Tag.Item...
Split a collection into `n` parts with LINQ?
... group item by i++ % parts into part
select part.AsEnumerable();
return splits;
}
}
share
|
improve this answer
|
follow
...
SQLite: How do I save the result of a query as a CSV file?
... file output.
sqlite> .mode csv
sqlite> .output test.csv
sqlite> select * from tbl1;
sqlite> .output stdout
share
|
improve this answer
|
follow
...