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What is the difference between bottom-up and top-down?
...ds the root.
Tabulation - You can also think of dynamic programming as a "table-filling" algorithm (though usually multidimensional, this 'table' may have non-Euclidean geometry in very rare cases*). This is like memoization but more active, and involves one additional step: You must pick, ahead of...
Cast int to varchar
...wing SQL — in action — over at SQL Fiddle:
/*! Build Schema */
create table t9 (id INT, name VARCHAR(55));
insert into t9 (id, name) values (2, 'bob');
/*! SQL Queries */
select CAST(id as CHAR(50)) as col1 from t9;
select CONVERT(id, CHAR(50)) as colI1 from t9;
Besides the fact that you w...
Where do you store your salt strings?
...
The point of rainbow tables is that they're created in advance and distributed en masse to save calculation time for others - it takes just as long to generate rainbow tables on the fly as it would to just crack the password+salt combination dire...
Restrict varchar() column to specific values?
...t on that column which would restrict values? Something like:
CREATE TABLE SomeTable
(
Id int NOT NULL,
Frequency varchar(200),
CONSTRAINT chk_Frequency CHECK (Frequency IN ('Daily', 'Weekly', 'Monthly', 'Yearly'))
)
...
Vertical (rotated) text in HTML table
Is there a (portable) way to rotate text in a HTML table cell by 90°?
11 Answers
11
...
Most efficient way to remove special characters from string
...ms.
The price to pay is, of course, the initialization of the huge lookup table and keeping it in memory. Well, it's not that much data, but it's much for such a trivial function...
private static bool[] _lookup;
static Program() {
_lookup = new bool[65536];
for (char c = '0'; c <= '9'; ...
Using group by on multiple columns
...one group.
To illustrate using an example, let's say we have the following table, to do with who is attending what subject at a university:
Table: Subject_Selection
+---------+----------+----------+
| Subject | Semester | Attendee |
+---------+----------+----------+
| ITB001 | 1 | John ...
How to return result of a SELECT inside a function in PostgreSQL?
...ERY:
CREATE OR REPLACE FUNCTION word_frequency(_max_tokens int)
RETURNS TABLE (txt text -- also visible as OUT parameter inside function
, cnt bigint
, ratio bigint) AS
$func$
BEGIN
RETURN QUERY
SELECT t.txt
, count(*) AS cnt -- co...
How to show multiline text in a table cell
I want to show a paragraph from database into a table cell.
10 Answers
10
...
Why can't a text column have a default value in MySQL?
If you try to create a TEXT column on a table, and give it a default value in MySQL, you get an error (on Windows at least). I cannot see any reason why a text column should not have a default value. No explanation is given by the MySQL documentation. It seems illogical to me (and somewhat frustrati...