大约有 45,000 项符合查询结果（耗时：0.0311秒） [XML]
Select top 10 records for each category
...
If you are using SQL 2005 you can do something like this...
SELECT rs.Field1,rs.Field2
FROM (
SELECT Field1,Field2, Rank()
over (Partition BY Section
ORDER BY RankCriteria DESC ) AS Rank
FROM table
) rs WHERE Rank <= 10
If y...
What is the reason not to use select *?
...eople claim that you should specifically name each column you want in your select query.
20 Answers
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How to automatically select all text on focus in WPF TextBox?
If I call SelectAll from a GotFocus event handler, it doesn't work with the mouse - the selection disappears as soon as mouse is released.
...
Multiple select statements in Single query
...
SELECT (
SELECT COUNT(*)
FROM user_table
) AS tot_user,
(
SELECT COUNT(*)
FROM cat_table
) AS tot_cat,
(
SELECT COUNT(*)
FROM course_table
) AS tot_course
...
Select n random rows from SQL Server table
I've got a SQL Server table with about 50,000 rows in it. I want to select about 5,000 of those rows at random. I've thought of a complicated way, creating a temp table with a "random number" column, copying my table into that, looping through the temp table and updating each row with RAND() , and ...
Simplest way to do a recursive self-join?
...
WITH q AS
(
SELECT *
FROM mytable
WHERE ParentID IS NULL -- this condition defines the ultimate ancestors in your chain, change it as appropriate
UNION ALL
SELECT m.*
FROM mytable m
...
SQL Server 2008: How to query all databases sizes?
...
with fs
as
(
select database_id, type, size * 8.0 / 1024 size
from sys.master_files
)
select
name,
(select sum(size) from fs where type = 0 and fs.database_id = db.database_id) DataFileSizeMB,
(select sum(size) from fs wh...
DISTINCT for only one column
...
If you are using SQL Server 2005 or above use this:
SELECT *
FROM (
SELECT ID,
Email,
ProductName,
ProductModel,
ROW_NUMBER() OVER(PARTITION BY Email ORDER BY ...
How to get sp_executesql result into a variable?
...
DECLARE @ParmDefinition nvarchar(500);
DECLARE @tablename nvarchar(50)
SELECT @tablename = N'products'
SELECT @sSQL = N'SELECT @retvalOUT = MAX(ID) FROM ' + @tablename;
SET @ParmDefinition = N'@retvalOUT int OUTPUT';
EXEC sp_executesql @sSQL, @ParmDefinition, @retvalOUT=@retval OUTPUT;
SE...
Preventing an image from being draggable or selectable without using JS
Does anyone know of a way to make an image not draggable and not selectable -- at the same time -- in Firefox, without resorting to Javascript? Seems trivial, but here's the issue:
...