IS NOT NULL in where clause : Null « Data Type « SQL / MySQL

Home
SQL / MySQL
1.Aggregate Functions
2.Backup Load
3.Command MySQL
4.Cursor
5.Data Type
6.Database
7.Date Time
8.Engine
9.Event
10.Flow Control
11.FullText Search
12.Function
13.Geometric
14.I18N
15.Insert Delete Update
16.Join
17.Key
18.Math
19.Procedure Function
20.Regular Expression
21.Select Clause
22.String
23.Table Index
24.Transaction
25.Trigger
26.User Permission
27.View
28.Where Clause
29.XML
SQL / MySQL » Data Type » Null 
IS NOT NULL in where clause
   
/*
mysql> Drop table Sale;
Query OK, 0 rows affected (0.00 sec)

mysql> CREATE TABLE Sale
    -> (
    ->    ID SMALLINT NOT NULL AUTO_INCREMENT PRIMARY KEY,
    ->    Name VARCHAR(50) NOT NULL,
    ->    InStock SMALLINT UNSIGNED NOT NULL,
    ->    OnOrder SMALLINT UNSIGNED NOT NULL,
    ->    Reserved SMALLINT UNSIGNED NOT NULL,
    ->    Department ENUM('Classical', 'Popular') NOT NULL,
    ->    Category VARCHAR(20)
    -> );
Query OK, 0 rows affected (0.12 sec)

mysql> INSERT INTO Sale (Name,      InStock, OnOrder, Reserved, Department, Cate
gory)
    -> VALUES          ('Bloodshot', 11,      6,       1,        'Popular',  'Ro
ck'),
    ->                 ('Opera',     12,      5,       2,        'Classical','Op
era'),
    ->                 ('Jazz',      13,      4,       3,        'Popular',  'Ja
zz'),
    ->                 ('Music',     4,       3,       4,        'Classical','Da
nce'),
    ->                 ('Violin',    25,      2,       5,        'Classical', NU
LL),
    ->                 ('Toscana',   16,      1,       6,        'Classical', NU
LL),
    ->                 ('Blues',     7,       22,      7,        'Popular',   'B
lues'),
    ->                 ('Pure',      38,      5,       11,       'Popular',   NU
LL),
    ->                 ('Mud',       19,      11,      12,       'Popular',  'Co
untry'),
    ->                 ('Essence',   5,       23,      12,       'Popular', 'New
 Age'),
    ->                 ('Embrace',   21,      12,      14,       'Popular', 'New
 Age'),
    ->                 ('Satie',     42,      17,      15,       'Classical', NU
LL),
    ->                 ('Lake',      23,      47,      28,       'Classical', 'D
ance'),
    ->                 ('Favorites', 34,      15,      12,       'Classical', 'G
eneral'),
    ->                 ('Boheme',    25,      12,       5,       'Classical', 'O
pera'),
    ->                 ('Cantatas',  26,      13,      8,        'Classical', 'G
eneral'),
    ->                 ('Road',      27,      13,      17,       'Popular', 'Cou
ntry'),
    ->                 ('Paris',     18,      25,      10,       'Popular', 'Jaz
z'),
    ->                 ('Woman',     29,      4,        7,       'Popular', 'Blu
es'),
    ->                 ('Bach',      21,      13,      16,       'Classical', 'G
eneral'),
    ->                 ('Opera',     12,      32,      12,       'Classical', 'O
pera'),
    ->                 ('Soul',      13,      30,      14,       'Popular', NULL
),
    ->                 ('Stages',    44,      0,       8,        'Popular', 'Blu
es'),
    ->                 ('Bach',      15,      1,       8,        'Classical', 'G
eneral');
Query OK, 24 rows affected (0.01 sec)
Records: 24  Duplicates: 0  Warnings: 0

mysql> select * from Sale;
+----+-----------+---------+---------+----------+------------+----------+
| ID | Name      | InStock | OnOrder | Reserved | Department | Category |
+----+-----------+---------+---------+----------+------------+----------+
|  1 | Bloodshot |      11 |       6 |        1 | Popular    | Rock     |
|  2 | Opera     |      12 |       5 |        2 | Classical  | Opera    |
|  3 | Jazz      |      13 |       4 |        3 | Popular    | Jazz     |
|  4 | Music     |       4 |       3 |        4 | Classical  | Dance    |
|  5 | Violin    |      25 |       2 |        5 | Classical  | NULL     |
|  6 | Toscana   |      16 |       1 |        6 | Classical  | NULL     |
|  7 | Blues     |       7 |      22 |        7 | Popular    | Blues    |
|  8 | Pure      |      38 |       5 |       11 | Popular    | NULL     |
|  9 | Mud       |      19 |      11 |       12 | Popular    | Country  |
| 10 | Essence   |       5 |      23 |       12 | Popular    | New Age  |
| 11 | Embrace   |      21 |      12 |       14 | Popular    | New Age  |
| 12 | Satie     |      42 |      17 |       15 | Classical  | NULL     |
| 13 | Lake      |      23 |      47 |       28 | Classical  | Dance    |
| 14 | Favorites |      34 |      15 |       12 | Classical  | General  |
| 15 | Boheme    |      25 |      12 |        5 | Classical  | Opera    |
| 16 | Cantatas  |      26 |      13 |        8 | Classical  | General  |
| 17 | Road      |      27 |      13 |       17 | Popular    | Country  |
| 18 | Paris     |      18 |      25 |       10 | Popular    | Jazz     |
| 19 | Woman     |      29 |       4 |        7 | Popular    | Blues    |
| 20 | Bach      |      21 |      13 |       16 | Classical  | General  |
| 21 | Opera     |      12 |      32 |       12 | Classical  | Opera    |
| 22 | Soul      |      13 |      30 |       14 | Popular    | NULL     |
| 23 | Stages    |      44 |       0 |        8 | Popular    | Blues    |
| 24 | Bach      |      15 |       1 |        8 | Classical  | General  |
+----+-----------+---------+---------+----------+------------+----------+
24 rows in set (0.01 sec)

mysql> SELECT Name, Department, Category
    -> FROM Sale
    -> WHERE Category IS NOT NULL
    -> ORDER BY Name;
+-----------+------------+----------+
| Name      | Department | Category |
+-----------+------------+----------+
| Bach      | Classical  | General  |
| Bach      | Classical  | General  |
| Bloodshot | Popular    | Rock     |
| Blues     | Popular    | Blues    |
| Boheme    | Classical  | Opera    |
| Cantatas  | Classical  | General  |
| Embrace   | Popular    | New Age  |
| Essence   | Popular    | New Age  |
| Favorites | Classical  | General  |
| Jazz      | Popular    | Jazz     |
| Lake      | Classical  | Dance    |
| Mud       | Popular    | Country  |
| Music     | Classical  | Dance    |
| Opera     | Classical  | Opera    |
| Opera     | Classical  | Opera    |
| Paris     | Popular    | Jazz     |
| Road      | Popular    | Country  |
| Stages    | Popular    | Blues    |
| Woman     | Popular    | Blues    |
+-----------+------------+----------+
19 rows in set (0.02 sec)


*/

Drop table Sale;


CREATE TABLE Sale
(
   ID SMALLINT NOT NULL AUTO_INCREMENT PRIMARY KEY,
   Name VARCHAR(50NOT NULL,
   InStock SMALLINT UNSIGNED NOT NULL,
   OnOrder SMALLINT UNSIGNED NOT NULL,
   Reserved SMALLINT UNSIGNED NOT NULL,
   Department ENUM('Classical', 'Popular') NOT NULL,
   Category VARCHAR(20)
);


INSERT INTO Sale (Name,      InStock, OnOrder, Reserved, Department, Category)
VALUES          ('Bloodshot', 11,      6,       1,        'Popular',  'Rock'),
                ('Opera',     12,      5,       2,        'Classical','Opera'),
                ('Jazz',      13,      4,       3,        'Popular',  'Jazz'),
                ('Music',     4,       3,       4,        'Classical','Dance'),
                ('Violin',    25,      2,       5,        'Classical', NULL),
                ('Toscana',   16,      1,       6,        'Classical', NULL),
                ('Blues',     7,       22,      7,        'Popular',   'Blues'),
                ('Pure',      38,      5,       11,       'Popular',   NULL),
                ('Mud',       19,      11,      12,       'Popular',  'Country'),
                ('Essence',   5,       23,      12,       'Popular', 'New Age'),
                ('Embrace',   21,      12,      14,       'Popular', 'New Age'),
                ('Satie',     42,      17,      15,       'Classical', NULL),
                ('Lake',      23,      47,      28,       'Classical', 'Dance'),
                ('Favorites', 34,      15,      12,       'Classical', 'General'),
                ('Boheme',    25,      12,       5,       'Classical', 'Opera'),
                ('Cantatas',  26,      13,      8,        'Classical', 'General'),
                ('Road',      27,      13,      17,       'Popular', 'Country'),
                ('Paris',     18,      25,      10,       'Popular', 'Jazz'),
                ('Woman',     29,      4,        7,       'Popular', 'Blues'),
                ('Bach',      21,      13,      16,       'Classical', 'General'),
                ('Opera',     12,      32,      12,       'Classical', 'Opera'),
                ('Soul',      13,      30,      14,       'Popular', NULL),
                ('Stages',    44,      0,       8,        'Popular', 'Blues'),
                ('Bach',      15,      1,       8,        'Classical', 'General');
  
select from Sale;


  
SELECT Name, Department, Category
FROM Sale
WHERE Category IS NOT NULL
ORDER BY Name;

           
         
    
    
  
Related examples in the same category
1.Retrieve NULL value
2.Concatenate string with NULL value
3.Working with NULL Values
4.Use the IS NULL and IS NOT NULL operators
5.NULL means 'not having a value'
6.Disallowing NULLs
7.Retrieve NOT NULL value
8.List NOT NULL value and order it
9.Select NOT NULL value
10.NULL value in where clause
11.Read NULL value
12.Dealing With NULL Data
13.An important one to note; the result is not 0 (false), it's NULL
14.To evaluate NULL rows
15.NULL is basically a third possible result of an evaluation: There's true, false, and then there's NULL.
16.Use the IS NULL (or IS NOT NULL) comparison instead
17.Assuming that NULL values sort ahead of all non-NULL values
18.Passing a NULL value to a function results in a NULL return value.
19.Set value to null
20.What is the result of the calculation 10 divided by 0?
21.If the value of an expression cannot be determined, the result is NULL:
java2s.com  | Contact Us | Privacy Policy
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.