sql - Union to handle NULL values - Stack Overflow
select a,b,null,null from table1 union select null,null,c,d from table2 union select null,null,null,null,e,f from table3.
999999.9 /**/union/**/all /**/select /**/cast...
select cast (2000 as type of quint) from rdb$database select cast (2000 as int) from rdb$database.
SQL NULL Values - IS NULL and IS NOT NULL
Note: A NULL value is different from a zero value or a field that contains spaces.
How to retreive only columns which having at least one not null value...
Union select null, null, null, null, null, null -- test all nulls --*/ ). A. DECLARE @ColumnDynamicSQL nvarchar(MAX)
Заметка про NULL / Хабр
Даже выражение NULL != NULL не будет истинным, ведь нельзя однозначно сравнить одну неизвестность с другой. Кстати, ложным это выражение тоже не будет, потому что при вычислении условий Oracle не ограничивается состояниями ИСТИНА и ЛОЖЬ.
Setting a char * to null | Forum
that's wrong though. (char*)NULL isn't a string at all, it's a null pointer. this isn't a string either even though it's an array of char.
Null-terminated string - Wikipedia
In computer programming, a null-terminated string is a character string stored as an array containing the characters and terminated with a null character ('\0', called NUL in ASCII). Alternative names are C string, which refers to the C programming language and ASCIIZ...
NULL in the Oracle Database: Even more special than SQL NULL
NULL handling in the Oracle database is even more special.
R null values: NULL, NA, NaN, Inf | R-bloggers
R language supports several null-able values and it is relatively important to understand how these values behave, when making data pre-processing and
SQL: IS NOT NULL Condition
The IS NOT NULL condition is used in SQL to test for a non-NULL value.