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Is there any boolean type in Oracle databases?
...efer char(1) because it uses less space. You can check it this way: create table testbool (boolc char(1), booln number(1)); insert into testbool values ('Y', 1 ); select dump(boolc), dump(booln) from testbool; That CHAR is stored: Typ=96 Len=1: 89 and that NUMBER: Typ=2 Len=2: 193,2 At least in 12c...
Display / print all rows of a tibble (tbl_df)
...ated by the dplyr data frame manipulation package in R. It prevents long table outputs when accidentally calling the data frame.
...
How to implement the activity stream in a social network
...rowse far back in time (if you even offer this)
I use a plain old MySQL table for dealing with about 15 million activities.
It looks something like this:
id
user_id (int)
activity_type (tinyint)
source_id (int)
parent_id (int)
parent_type (tinyint)
time (...
How can I insert values into a table, using a subquery with more than one result?
...
If you are inserting one record into your table, you can do
INSERT INTO yourTable
VALUES(value1, value2)
But since you want to insert more than one record, you can use a SELECT FROM in your SQL statement.
so you will want to do this:
INSERT INTO prices (group,...
What good are SQL Server schemas?
...
Schemas logically group tables, procedures, views together. All employee-related objects in the employee schema, etc.
You can also give permissions to just one schema, so that users can only see the schema they have access to and nothing else.
...
Remove all spaces from a string in SQL Server
... trim() or worry about multiple spaces for either char or varchar:
create table #t (
c char(8),
v varchar(8))
insert #t (c, v) values
('a a' , 'a a' ),
('a a ' , 'a a ' ),
(' a a' , ' a a' ),
(' a a ', ' a a ')
select
'"' + c + '"' [IN], '"' + replac...
Find all records which have a count of an association greater than zero
...s a matter of preference. The count can be done with any field in the join table that is guaranteed to have a value in every row. Most meaningful candidates are projects.id, project_id, and vacancies.id. I chose to count project_id because it is the field on which the join is made; the spine of the ...
Why shouldn't I use mysql_* functions in PHP?
...ing mysql_* is:
//Connected to MySQL
$result = mysql_query("SELECT * FROM table", $link) or die(mysql_error($link));
OR die() is not a good way to handle the error since we can not handle the thing in die. It will just end the script abruptly and then echo the error to the screen which you usuall...
'Incomplete final line' warning when trying to read a .csv file into R
...here's no way that in your case the warning was thrown by the function readTableHeader, because that one doesn't read the final line. Hence your problem is not the same as that of the OP.
– Joris Meys
May 1 at 11:31
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What are the differences between virtual memory and physical memory?
...perating system creates and deals with these mappings - utilizing the page table, among other data structures to maintain the mappings. Virtual memory mappings are always found in the page table or some similar data structure (in case of other implementations of virtual memory, we maybe shouldn't ca...