大约有 40,000 项符合查询结果（耗时：0.0263秒） [XML]
SQL statement to get column type
...
Using SQL Server:
SELECT DATA_TYPE
FROM INFORMATION_SCHEMA.COLUMNS
WHERE
TABLE_NAME = 'yourTableName' AND
COLUMN_NAME = 'yourColumnName'
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Retrieving the last record in each group - MySQL
...x, we can write greatest-n-per-group queries:
WITH ranked_messages AS (
SELECT m.*, ROW_NUMBER() OVER (PARTITION BY name ORDER BY id DESC) AS rn
FROM messages AS m
)
SELECT * FROM ranked_messages WHERE rn = 1;
Below is the original answer I wrote for this question in 2009:
I write the solu...
When restoring a backup, how do I disconnect all active connections?
... the steps (via: Tim Leung)
Right-click the server in Object Explorer and select 'Activity Monitor'.
When this opens, expand the Processes group.
Now use the drop-down to filter the results by database name.
Kill off the server connections by selecting the right-click 'Kill Process' option.
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How to check Oracle database for long running queries
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This one shows SQL that is currently "ACTIVE":-
select S.USERNAME, s.sid, s.osuser, t.sql_id, sql_text
from v$sqltext_with_newlines t,V$SESSION s
where t.address =s.sql_address
and t.hash_value = s.sql_hash_value
and s.status = 'ACTIVE'
and s.username <> 'SYSTEM'
ord...
Oracle query to fetch column names
...r case, I'd imagine the query would look something like:
String sqlStr= "
SELECT column_name
FROM all_tab_cols
WHERE table_name = 'USERS'
AND owner = '" +_db+ "'
AND column_name NOT IN ( 'PASSWORD', 'VERSION', 'ID' )"
Note that with this approach, you risk SQL injection.
EDIT: Uppercase...
Difference between a theta join, equijoin and natural join
...ed SQL query would be like this (you can play with all the examples here)
SELECT *
FROM Product
JOIN Component
ON Product.Pname = Component.Pname
and the result:
| PNAME | PRICE | CNAME | COST |
----------------------------------
| Laptop | 1500 | CPU | 500 |
| Laptop | 1500 | hdd ...
Replacement for “rename” in dplyr
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The next version of dplyr will support an improved version of select that also incorporates renaming:
> mtcars2 <- select( mtcars, disp2 = disp )
> head( mtcars2 )
disp2
Mazda RX4 160
Mazda RX4 Wag 160
Datsun 710 108
Hornet 4 Drive 258
H...
How to export query result to csv in Oracle SQL Developer?
...worksheet toolbar)
That's it.
Method 2
Run a query
Right click and select unload.
Update. In Sql Developer Version 3.0.04 unload has been changed to export
Thanks to Janis Peisenieks for pointing this out
Revised screen shot for SQL Developer Version 3.0.04
From the format drop down...
How to get a date in YYYY-MM-DD format from a TSQL datetime field?
...
SELECT CONVERT(char(10), GetDate(),126)
Limiting the size of the varchar chops of the hour portion that you don't want.
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IntelliJ: Viewing diff of all changed files between local and a git commit/branch
... new UI, click on Show Diff with Working Tree
Next a window will pop up. Select Files and press cmd + d
Another window which shows diff. You can perform many different types of diff. Use cmd + shift + ] and cmd + shift + [ to shift between files.
Diff Tip: IntelliJ provides advanced diff feat...