大约有 44,000 项符合查询结果（耗时：0.0604秒） [XML]
Rails: How can I set default values in ActiveRecord?
...
See Paul Russell's comment on this answer for more details
If you're only selecting a subset of columns for a model (ie; using select in a query like Person.select(:firstname, :lastname).all) you will get a MissingAttributeError if your init method accesses a column that hasn't been included in the...
Using “like” wildcard in prepared statement
...place("[", "![");
PreparedStatement pstmt = con.prepareStatement(
"SELECT * FROM analysis WHERE notes LIKE ? ESCAPE '!'");
pstmt.setString(1, notes + "%");
or a suffix-match:
pstmt.setString(1, "%" + notes);
or a global match:
pstmt.setString(1, "%" + notes + "%");
...
Storing time-series data, relational or non?
...evation.
Correction
It is not "filtering out the un-needed data"; it is selecting only the needed data. Yes, of course, if you have an Index to support the columns identified in the WHERE clause, it is very fast, and the query does not depend on the size of the table (grabbing 1,000 rows from a ...
Java 256-bit AES Password-Based Encryption
...
Share the password (a char[]) and salt (a byte[]—8 bytes selected by a SecureRandom makes a good salt—which doesn't need to be kept secret) with the recipient out-of-band. Then to derive a good key from this information:
/* Derive the key, given password and salt. */
SecretKeyFa...
What is the difference between '>' and a space in CSS selectors?
...
A > B will only select B that are direct children to A (that is, there are no other elements inbetween).
A B will select any B that are inside A, even if there are other elements between them.
...
What is PostgreSQL explain telling me exactly?
...ly 1 sentence of technical content: "• EXPLAIN works on any DML not just SELECT (ie UPDATE, DELETE, and INSERT)". My biggest misunderstanding is what "startup" time means, and that's not explained anywhere in these ~30 slides.
– Mark E. Haase
Feb 19 '16 at 15...
Cannot drop database because it is currently in use
...ar(50)
SET @DatabaseName = N'YOUR_DABASE_NAME'
DECLARE @SQL varchar(max)
SELECT @SQL = COALESCE(@SQL,'') + 'Kill ' + Convert(varchar, SPId) + ';'
FROM MASTER..SysProcesses
WHERE DBId = DB_ID(@DatabaseName) AND SPId <> @@SPId
--SELECT @SQL
EXEC(@SQL)
...
Which is better: … or …
...PT - - %Script; -- script statements -->
<!ATTLIST SCRIPT
charset %Charset; #IMPLIED -- char encoding of linked resource --
type %ContentType; #REQUIRED -- content type of script language --
src %URI; #IMPLIED -- URI for an external script --
...
HTML5 input type range show range value
...iding fancy widgets is not the role of the basic standard, but showing the selected value is core to this widget, so I think that (optionally) showing the number in a basic form such as a tooltip on top of the slider handle would make for a better design.
– Basel Shishani
...
Ensuring json keys are lowercase in .NET
...ntratResolver do not transform the properties in lowercase, just the first char.
– ToXinE
Sep 18 '15 at 8:26
...