大约有 12,000 项符合查询结果（耗时：0.0201秒） [XML]
IN clause and placeholders
...mes = { "name1", "name2" }; // do whatever is needed first
String query = "SELECT * FROM table"
+ " WHERE name IN (" + makePlaceholders(names.length) + ")";
Cursor cursor = mDb.rawQuery(query, names);
Just make sure to pass exactly as many values as places. The default maximum limit of host pa...
Is there a better way to dynamically build an SQL WHERE clause than by using 1=1 at its beginning?
... {2}", clause, appender, condition);
}
Use it like this
string query = "SELECT * FROM Table1 {0}";
string whereClause = string.Empty;
if (condition 1)
whereClause = AddCondition(whereClause, "AND", "Col=1");
if (condition 2)
whereClause = AddCondition(whereClause, "AND", "Col2=2");
str...
What is the most efficient/elegant way to parse a flat table into a tree?
...port recursive queries in standard syntax.
WITH RECURSIVE MyTree AS (
SELECT * FROM MyTable WHERE ParentId IS NULL
UNION ALL
SELECT m.* FROM MyTABLE AS m JOIN MyTree AS t ON m.ParentId = t.Id
)
SELECT * FROM MyTree;
I tested recursive queries in MySQL 8.0 in my presentation Recursive ...
Only read selected columns
...from the data.table-package:
You can specify the desired columns with the select parameter from fread from the data.table package. You can specify the columns with a vector of column names or column numbers.
For the example dataset:
library(data.table)
dat <- fread("data.txt", select = c("Year...
How to use a class from one C# project with another C# project
...Explorer' tree, expand the P2 project and then right-click the project and select 'Add Reference' from the menu.
On the 'Add Reference' dialog, select the 'Projects' tab and select your P1 project.
If you are using namespaces then you will need to import the namespaces for your P1 types by adding ...
Checking oracle sid and database name
...
I presume SELECT user FROM dual; should give you the current user
and SELECT sys_context('userenv','instance_name') FROM dual; the name of the instance
I believe you can get SID as SELECT sys_context('USERENV', 'SID') FROM DUAL;
...
How to insert text at beginning of a multi-line selection in vi/Vim
In Vim , how do I insert characters at the beginning of each line in a selection?
13 Answers
...
How to use Oracle ORDER BY and ROWNUM correctly?
...n Oracle.
If you want a version that works in both servers, you can use:
select ril.*
from (select ril.*, row_number() over (order by t_stamp desc) as seqnum
from raceway_input_labo ril
) ril
where seqnum = 1
The outer * will return "1" in the last column. You would need to list the ...
How can I make an entire HTML form “readonly”?
...e="text" name="something" placeholder="enter some text" />
<select>
<option value="0" disabled="disabled" selected="selected">select somethihng</option>
<option value="1">woot</option>
<option value="2">is</opt...
In jQuery, how do I select an element by its name attribute?
...
Good point. Although it's still not "How to get selected radiobutton value using its name in jQuery?". It's "How to get selected radiobutton value when clicking on it using jQuery?". A small difference, but one that baffled me for a bit.
– gargantuan
...