大约有 3,562 项符合查询结果（耗时：0.0108秒） [XML]
Many-to-many relationship with the same model in rails?
...t seen when simply accessing the associations from irb, and looking at the SQL that Rails generates in the log file. You'll find something like the following:
SELECT * FROM "posts"
INNER JOIN "post_connections" ON "posts".id = "post_connections".post_b_id
WHERE ("post_connections".post_a_id = 1 )
...
WCF timeout exception detailed investigation
...ize the objects you are returning. Specifically, if you are using Linq-To-Sql objects that have relationships, there are known serialization problems if you put a back reference on a child object to the parent object and mark that back reference as a DataMember.
You can verify serialization by wri...
How does “cat
I needed to write a script to enter multi-line input to a program ( psql ).
9 Answers
...
String.Join method that ignores empty strings?
...
To do it in .NET 2.0 (no LINQ), e.g. for SQL-Server ReportingServices without having to write a function for it:
VB.NET
Dim a As String = "", b As String = "b", c As String = "", d As String = "d", e As String = ""
Dim lala As String = String.Join(" / ", String.J...
Best practices for in-app database migration for Sqlite
I am using sqlite for my iphone and I anticipate the database schema might change over time. What are the gotchas, naming conventions and things to watch out for to do a successful migration each time?
...
generate days from date range
...portable technique that works with most databases with minor adjustments.
SQL Fiddle example returning 1,000 days
share
|
improve this answer
|
follow
|
...
Why unsigned integer is not available in PostgreSQL?
...s the difference between tinyint, smallint, mediumint, bigint and int in MySQL? ) and realized that PostgreSQL does not support unsigned integer.
...
Select rows which are not present in other table
I've got two postgresql tables:
4 Answers
4
...
Advantages and disadvantages of GUID / UUID database keys
...
Hear hear! Love your SQL comparison page btw. Extremely useful. The only thing I miss is a changelog.
– Henrik Gustafsson
Sep 16 '08 at 20:40
...
Can you use an alias in the WHERE clause in mysql?
...ll not work, in which case you'll need to use a HAVING clause.
From the MySQL Manual:
It is not allowable to refer to a
column alias in a WHERE clause,
because the column value might not yet
be determined when the WHERE clause
is executed. See Section B.1.5.4,
“Problems with Column...