null Questions
9
Solved
Postgres is the database
Can I use a NULL value for a IN clause? example:
SELECT *
FROM tbl_name
WHERE id_field IN ('value1', 'value2', 'value3', NULL)
I want to limit to these four values.
I ...
Urbani asked 15/6, 2011 at 17:59
4
Solved
I have some code where variable used in the WHERE clause could be nullable. As a result I have to query data using IF ELSE to check for NULL. Is there anyway of writing in in one query?
DECLARE @...
Orlosky asked 30/10, 2013 at 13:0
26
I'm looking to make my code more readable as well as use tooling like IDE code inspection and/or static code analysis (FindBugs and Sonar) to avoid NullPointerExceptions. Many of the tools seem inc...
Atmolysis asked 10/2, 2011 at 22:5
6
I saw many questions regarding this error, but all/most of them contain complex code or types.
I used this line for many years to prompt the name of the method with an error:
string currentMethod =...
16
Solved
I've written a couple of functions that effectively replicate JSON.stringify(), converting a range of values into stringified versions. When I port my code over to JSBin and run it on some sample v...
Appledorf asked 18/4, 2015 at 18:29
30
Solved
Is there any way to determine (programatically, of course) if a given pointer is "valid"? Checking for NULL is easy, but what about things like 0x00001234? When trying to dereference this kind of p...
Tartuffery asked 15/2, 2009 at 15:45
4
I am writing my own simple javax.sql.DataSource implementation, the only method of it I need to work is getConnection: Connection, but the interface inherits many other methods (which I don't need)...
6
Solved
Is it possible to convert null to string with php?
For instance,
$string = null;
to
$string = "null";
3
The error
Cannot delete or update a parent row: a foreign key constraint fails.
The classes
class Teacher {
/**
*@ORM\OneToMany(targetEntity="publication", mappedBy="teacher")
*/
protected ...
Biddable asked 13/1, 2012 at 23:29
11
Solved
How can I set a Hibernate Parameter to "null"? Example:
Query query = getSession().createQuery("from CountryDTO c where c.status = :status and c.type =:type")
.setParameter("status", status, Hiber...
5
Solved
Hello im getting the following error while upload an image using laravel: "Call to a member function getClientOriginalExtension() on null".
Here is my controller:
$imageName = rand(11111, 99999) ...
7
Solved
When a Java VM crashes with an EXCEPTION_ACCESS_VIOLATION and produces an hs_err_pidXXX.log file, what does that indicate? The error itself is basically a null pointer exception. Is it always cause...
9
Solved
I ran a program on Windows 7 that was compiled under Cygwin and passed "NUL" as an output file name. Instead of suppressing output it actually created a file named "NUL" in the current directory. (...
3
Solved
I'm working with vectors and at some point there will be NULL entries; I want to erase all NULL occurrences within the given vectors. My approach so far is not working:
for(int i = sent_flit_list-...
4
Solved
I have a dataframe which contains null values:
from pyspark.sql import functions as F
df = spark.createDataFrame(
[(125, '2012-10-10', 'tv'),
(20, '2012-10-10', 'phone'),
(40, '2012-10-10', 'tv...
Gowrie asked 5/2, 2018 at 21:50
16
Solved
Is there a built-in IsNullOrEmpty-like function in order to check if a string is null or empty, in PowerShell?
I could not find it so far and if there is a built-in way, I do not want to write a f...
Sorority asked 6/12, 2012 at 7:9
2
I have trouble understanding what happens in the oracle database after this sql is executed:
CREATE TABLE EMPTYSTRING
(
COLUMNA VARCHAR2(1)
);
INSERT INTO EMPTYSTRING (COLUMNA) VALUES('X');
ALT...
Tarter asked 28/2, 2014 at 10:0
5
Solved
I have a vector of lists and I use unlist on them. Some of the elements in the vectors are NULL and unlist seems to be dropping them.
How can I prevent this?
Here's a simple (non) working example...
4
Solved
In C# I can write code to check for null references and in case throw a custom exception, example:
var myValue = (someObject?.SomeProperty ?? throw new Exception("...")).SomeProperty;
In recent ...
Heavyset asked 27/3, 2020 at 10:44
10
Solved
Does the method get called with a null value or does it give a null reference exception?
MyObject myObject = null;
myObject.MyExtensionMethod(); // <-- is this a null reference exception?
If ...
Sickler asked 11/5, 2009 at 8:35
3
Solved
Need to insert null value to field with uuid type without NOT NULL specification (not primary key).
When I try insert '', this return:
ERROR: invalid input syntax for uuid: ""
When I try insert...
Dumpish asked 18/11, 2014 at 11:7
6
Solved
I have a large table with say 10 columns. 4 of them remains null most of the times. I have a query that does null value takes any size or no size in bytes. I read few articles some of them are sayi...
Bloodless asked 16/9, 2010 at 22:1
4
Solved
I have this code, you can try on db-fiddle:
CREATE TABLE EMPLOYEE
( ID INT,
Name VARCHAR(15) NOT NULL,
Age INT,
Dnumber INT,
Level INT,
PRIMARY KEY (ID)
);
INSERT INTO EMPLOYEE (ID, Name, Age...
9
Solved
Column1 Column2
------- -------
apple juice
water melon
banana
red berry
I have a table which has two columns. Column1 has a group of words and Column2 also has a group of words. I want to co...
Anesthetic asked 22/11, 2011 at 20:59
7
Solved
Is code that uses the static Object.Equals to check for null more robust than code that uses the == operator or regular Object.Equals? Aren't the latter two vulnerable to being overridden in such a...
Hydrocarbon asked 17/8, 2010 at 22:11
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