MySQL expresión equivalente a '0000-00-00 00:00:00'

Question

me gustaría saber si existe alguna expresión más corta, que esto:

'0000-00-00 00:00:00' 


SELECT id FROM orders WHERE posted='0000-00-00 00:00:00' ORDER BY id DESC LIMIT 1; 

quiero decir algo como:

SELECT id FROM orders WHERE posted=null ORDER BY id DESC LIMIT 1; 

espero que este es el esquema que quería ver:

array(19) { 
    ["TABLE_CATALOG"]=> 
    NULL 
    ["TABLE_SCHEMA"]=> 
    string(13) "teleprintfejl" 
    ["TABLE_NAME"]=> 
    string(13) "megrendelesek" 
    ["COLUMN_NAME"]=> 
    string(7) "posted" 
    ["ORDINAL_POSITION"]=> 
    string(2) "20" 
    ["COLUMN_DEFAULT"]=> 
    NULL 
    ["IS_NULLABLE"]=> 
    string(2) "NO" 
    ["DATA_TYPE"]=> 
    string(8) "datetime" 
    ["CHARACTER_MAXIMUM_LENGTH"]=> 
    NULL 
    ["CHARACTER_OCTET_LENGTH"]=> 
    NULL 
    ["NUMERIC_PRECISION"]=> 
    NULL 
    ["NUMERIC_SCALE"]=> 
    NULL 
    ["CHARACTER_SET_NAME"]=> 
    NULL 
    ["COLLATION_NAME"]=> 
    NULL 
    ["COLUMN_TYPE"]=> 
    string(8) "datetime" 
    ["COLUMN_KEY"]=> 
    string(0) "" 
    ["EXTRA"]=> 
    string(0) "" 
    ["PRIVILEGES"]=> 
    string(31) "select,insert,update,references" 
    ["COLUMN_COMMENT"]=> 
    string(0) "" 
} 

Answer 1

supongo que es una postedDATETIME. Puede usar 0.

posted = '0000-00-00 00:00:00' 

es lo mismo que

posted = 0 

Answer 2

que depende de su estructura, al crearlo, puede utilizar nulo por defecto y WH en haces un selecto que va a utilizar:

SELECT id FROM orders WHERE posted IS null ORDER BY id DESC LIMIT 1; 

EDIT:

mysql> create table tiempo (fecha datetime); 
Query OK, 0 rows affected (0.04 sec) 

mysql> insert into tiempo values(); 
Query OK, 1 row affected (0.00 sec) 

mysql> select * from tiempo; 
+-------+ 
| fecha | 
+-------+ 
| NULL | 
+-------+ 
1 row in set (0.00 sec) 

mysql> insert into tiempo values ('2000-02-02 02:02:02'); 
Query OK, 1 row affected (0.00 sec) 

mysql> select * from tiempo; 
+---------------------+ 
| fecha    | 
+---------------------+ 
| NULL    | 
| 2000-02-02 02:02:02 | 
+---------------------+ 
2 rows in set (0.00 sec) 

mysql> select * from tiempo where fecha is not null; 
+---------------------+ 
| fecha    | 
+---------------------+ 
| 2000-02-02 02:02:02 | 
+---------------------+ 
1 row in set (0.00 sec) 

Answer 3

SELECT max(id) as id FROM orders WHERE posted=0;