大约有 47,000 项符合查询结果（耗时：0.0263秒） [XML]
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 “select where not in subquery” returns no results
...MySQL
There are three ways to do such a query:
LEFT JOIN / IS NULL:
SELECT *
FROM common
LEFT JOIN
table1 t1
ON t1.common_id = common.common_id
WHERE t1.common_id IS NULL
NOT EXISTS:
SELECT *
FROM common
WHERE NOT EXISTS
(
SELECT NULL
FROM ...
How to use NULL or empty string in SQL
...
Select *
From Table
Where (col is null or col = '')
Or
Select *
From Table
Where IsNull(col, '') = ''
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Remove outline from select box in FF
Is it possible to remove the dotted line surrounding a selected item in a select element?
12 Answers
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What is the purpose of Order By 1 in SQL select statement?
...number stands for the column based on the number of columns defined in the SELECT clause. In the query you provided, it means:
ORDER BY A.PAYMENT_DATE
It's not a recommended practice, because:
It's not obvious/explicit
If the column order changes, the query is still valid so you risk ordering ...
SQL statement to select all rows from previous day
I am looking for a good SQL Statement to select all rows from the previous day from one table. The table holds one datetime column. I am using SQL Server 2005.
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SQL - find records from one table which don't exist in another
...shortest statement, and may be quickest if your phone book is very short:
SELECT *
FROM Call
WHERE phone_number NOT IN (SELECT phone_number FROM Phone_book)
alternatively (thanks to Alterlife)
SELECT *
FROM Call
WHERE NOT EXISTS
(SELECT *
FROM Phone_book
WHERE Phone_book.phon...
MySQL selecting yesterday's date
...get yesterday's date is:
subdate(current_date, 1)
Your query would be:
SELECT
url as LINK,
count(*) as timesExisted,
sum(DateVisited between UNIX_TIMESTAMP(subdate(current_date, 1)) and
UNIX_TIMESTAMP(current_date)) as timesVisitedYesterday
FROM mytable
GROUP BY 1
For the ...
Table name as variable
...mpare data between the same tables of different databases:
static query:
SELECT * FROM [DB_ONE].[dbo].[ACTY]
EXCEPT
SELECT * FROM [DB_TWO].[dbo].[ACTY]
since I want easily change tha name of table and schema I have created this dynamic query:
declare @schema varchar(50)
declare @table varchar(5...
Include headers when using SELECT INTO OUTFILE?
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You'd have to hard code those headers yourself. Something like:
SELECT 'ColName1', 'ColName2', 'ColName3'
UNION ALL
SELECT ColName1, ColName2, ColName3
FROM YourTable
INTO OUTFILE '/path/outfile'
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