大约有 46,000 项符合查询结果(耗时:0.0330秒) [XML]
How to select a single field for all documents in a MongoDB collection?
...nt such as:
db.student.find({}, {roll:1, _id:0})
The above statement will select all documents in the students collection, and the returned document will return only the roll field (and exclude the _id).
If we don't mention _id:0 the fields returned will be roll and _id. The '_id' field is always d...
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))
...
getting the ng-object selected with ng-change
Given the following select element
10 Answers
10
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Html.DropdownListFor selected value not being set
How can I set the selected value of a Html.DropDownListFor? I've been having a look online and have seen that it can be achieved by using the fourth parameter so like the below:
...
Oracle Differences between NVL and Coalesce
...the first non-NULL (there are some exceptions, such as sequence NEXTVAL):
SELECT SUM(val)
FROM (
SELECT NVL(1, LENGTH(RAWTOHEX(SYS_GUID()))) AS val
FROM dual
CONNECT BY
level <= 10000
)
This runs for almost 0.5 seconds, since it generates...
How can I list ALL grants a user received?
...ust direct table grants (e.g., grants via roles, system privileges such as select any table, etc.), here are some additional queries:
System privileges for a user:
SELECT PRIVILEGE
FROM sys.dba_sys_privs
WHERE grantee = <theUser>
UNION
SELECT PRIVILEGE
FROM dba_role_privs rp JOIN role_...
Select arrow style change
I'm trying to replace the arrow of a select with a picture of my own. I'm including the select in a div with the same size, I set the background of the select as transparent and I'm including a picture(with the same size as the arrow) in the right top corner of the div as background.
...
Sublime Text 2 multiple line edit
...t and edit all lines at once.
It's also called "Split into Lines" in the "Selection" menu.
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PostgreSQL return result set as JSON array?
...
TL;DR
SELECT json_agg(t) FROM t
for a JSON array of objects, and
SELECT
json_build_object(
'a', json_agg(t.a),
'b', json_agg(t.b)
)
FROM t
for a JSON object of arrays.
List of objects
This section de...
Fastest way to determine if record exists
...
SELECT TOP 1 products.id FROM products WHERE products.id = ?; will outperform all of your suggestions as it will terminate execution after it finds the first record.
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