大约有 40,000 项符合查询结果（耗时：0.0258秒） [XML]
Copy/duplicate database without using mysqldump
...the references, you can run the following to copy the data:
INSERT INTO x SELECT * FROM other_db.y;
If you're using MyISAM, you're better off to copy the table files; it'll be much faster. You should be able to do the same if you're using INNODB with per table table spaces.
If you do end up doin...
Which Radio button in the group is checked?
...g tri-state buttons, then I always set one button "IsChecked" as a default selection.)
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Select DISTINCT individual columns in django?
I'm curious if there's any way to do a query in Django that's not a " SELECT * FROM... " underneath. I'm trying to do a " SELECT DISTINCT columnName FROM ... " instead.
...
Can I combine :nth-child() or :nth-of-type() with an arbitrary selector?
Is there a way to select every nth child that matches (or does not match) an arbitrary selector ? For example, I want to select every odd table row, but within a subset of the rows:
...
How to insert text into the textarea at the current cursor position?
...ction insertAtCursor(myField, myValue) {
//IE support
if (document.selection) {
myField.focus();
sel = document.selection.createRange();
sel.text = myValue;
}
//MOZILLA and others
else if (myField.selectionStart || myField.selectionStart == '0') {
...
SQL query to get all values a enum can have
...
If you want an array:
SELECT enum_range(NULL::myenum)
If you want a separate record for each item in the enum:
SELECT unnest(enum_range(NULL::myenum))
Additional Information
This solution works as expected even if your enum is not in the...
Entity Framework and SQL Server View
...mn as a primary key, use NULLIF.
An easy way to apply this is to wrap the select statement of your view in another select.
Example:
SELECT
ISNULL(MyPrimaryID,-999) MyPrimaryID,
NULLIF(AnotherProperty,'') AnotherProperty
FROM ( ... ) AS temp
...
byte[] to hex string [duplicate]
...);
}
static string LinqConcat(byte[] data)
{
return string.Concat(data.Select(b => b.ToString("X2")).ToArray());
}
static string LinqJoin(byte[] data)
{
return string.Join("",
data.Select(
bin => bin.ToString("X2")
).ToArray());
}
static string LinqAgg(b...
SQL Server - where is “sys.functions”?
... easy enough to roll your own:
CREATE VIEW my_sys_functions_equivalent
AS
SELECT *
FROM sys.objects
WHERE type IN ('FN', 'IF', 'TF') -- scalar, inline table-valued, table-valued
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How to drop columns by name in a data frame
..."z","u"))]
x y
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Or, much simpler, use the select argument of the subset function : you can then use the - operator directly on a vector of column names, and you can even omit the quotes around the names !
R> subset(df, select=-c(z,u))
x y
1 1 2
2 2 3
3 3 4
4 4 ...