大约有 40,000 项符合查询结果（耗时：0.0268秒） [XML]
How do you convert a DataTable into a generic list?
...ataTable
//using lamdaexpression
emp = (from DataRow row in dt.Rows
select new Employee
{
_FirstName = row["FirstName"].ToString(),
_LastName = row["Last_Name"].ToString()
}).ToList();
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CSS Child vs Descendant selectors
I am a bit confused between these 2 selectors.
8 Answers
8
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How do I get textual contents from BLOB in Oracle SQL
...S of the text stored in the BLOB, CS of the database used for VARCHAR2) :
select utl_raw.cast_to_varchar2(dbms_lob.substr(BLOB_FIELD)) from TABLE_WITH_BLOB where ID = '<row id>';
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imp...
How dangerous is it to compare floating point values?
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[The 'right answer' glosses over selecting K. Selecting K ends up being just as ad-hoc as selecting VISIBLE_SHIFT but selecting K is less obvious because unlike VISIBLE_SHIFT it is not grounded on any display property. Thus pick your poison - select K or s...
-didSelectRowAtIndexPath: not being called
...de a tab view. In my UITableViewController , I implemented -tableView:didSelectRowAtIndexPath: , but when I select a row at runtime, the method isn't being called. The table view is being populated though, so I know that other tableView methods in my controller are being called.
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Vim: How to insert in visual block mode?
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Try this
After selecting a block of text, press Shift+i or capital I.
Lowercase i will not work.
Then type the things you want and finally to apply it to all lines, press Esc twice.
If this doesn't work...
Check if you have +visualextra ...
Extract date (yyyy/mm/dd) from a timestamp in PostgreSQL
... to a date by suffixing it with ::date. Here, in psql, is a timestamp:
# select '2010-01-01 12:00:00'::timestamp;
timestamp
---------------------
2010-01-01 12:00:00
Now we'll cast it to a date:
wconrad=# select '2010-01-01 12:00:00'::timestamp::date;
date
------------
201...
How do you list the primary key of a SQL Server table?
...
SELECT Col.Column_Name from
INFORMATION_SCHEMA.TABLE_CONSTRAINTS Tab,
INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE Col
WHERE
Col.Constraint_Name = Tab.Constraint_Name
AND Col.Table_Name = Tab.Table_Name
...
postgresql - sql - count of `true` values
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SELECT COALESCE(sum(CASE WHEN myCol THEN 1 ELSE 0 END),0) FROM <table name>
or, as you found out for yourself:
SELECT count(CASE WHEN myCol THEN 1 END) FROM <table name>
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How can I use optional parameters in a T-SQL stored procedure?
...ame varchar(25) = null,
@Title varchar(25) = null
AS
BEGIN
SELECT ID, FirstName, LastName, Title
FROM tblUsers
WHERE
(@FirstName IS NULL OR (FirstName = @FirstName))
AND (@LastName IS NULL OR (LastName = @LastName ))
AND (@Tit...