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What is a regular expression for a MAC Address?
... The second will incorrectly match strings which contain non-hex characters such as g.
– Binary Phile
Feb 25 '15 at 15:32
...
How to remove all whitespace from a string?
...paces before, after and in between
" \u2190 \u2192 ", # contains unicode chars
paste0( # varied whitespace
whitespace,
"x",
whitespace,
"y",
whitespace,
collapse = ""
),
NA # missing
)
## [1] " x y "
#...
How to use count and group by at the same select statement
I have an sql select query that has a group by.
I want to count all the records after the group by statement.
Is there a way for this directly from sql?
For example, having a table with users I want to select the different towns and the total number of users
...
Lost my schema.rb! Can it be regenerated?
... answered Oct 17 '16 at 2:18
R.ChaR.Cha
63566 silver badges1212 bronze badges
...
How to declare a variable in MySQL?
...at has not been
initialized, it has a value of NULL and a type of string.
SELECT @var_any_var_name
You can initialize a variable using SET or SELECT statement:
SET @start = 1, @finish = 10;
or
SELECT @start := 1, @finish := 10;
SELECT * FROM places WHERE place BETWEEN @start AND @finish...
How to select unique records by SQL
When I perform "SELECT * FROM table" I got results like below:
8 Answers
8
...
Select2 dropdown but allow new values by user?
I want to have a dropdown with a set of values but also allow the user to "select" a new value not listed there.
9 Answers...
How to create a table from select query result in SQL Server 2008 [duplicate]
I want to create a table from select query result in SQL Server, I tried
6 Answers
6
...
Meaning of $? (dollar question mark) in shell scripts
...k() == 0) {
/* Call false. */
execl("./false", "./false", (char *)NULL);
}
int status;
/* Wait for a child to finish. */
wait(&status);
/* Status encodes multiple fields,
* we need WEXITSTATUS to get the exit status:
* http://stackoverflow.com/questi...
SQLite with encryption/password protection
...ing str)
{
byte[] bytes = new byte[str.Length * sizeof(char)];
bytes = System.Text.Encoding.Default.GetBytes(str);
return bytes;
}
}
}
Optionally, you can remove conn.SetPassword(passwordBytes);, and replace it with conn.ChangePassword("passw...