union all select null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null.
select a,b,null,null from table1 union select null,null,c,d from table2 union select null,null,null,null,e,f
select cast (2000 as type of quint) from rdb$database select cast (2000 as int) from rdb$database. If TYPE OF is used with a (VAR)CHAR type, its character.
Then in the second table I have select ..., null as opt from... I know that I could have an empty string with '' as opt however, I don't want an empty string, I really do need it to be null.
Union select null, null, null, null, null, null, null from information_schema.tables. for a small database containing three tables. this instruction is used in sql injection I tried it and it worked but I didn't really know how it works can somebody help me...
The null character (also null terminator or null byte) is a control character with the value zero. It is present in many character sets, including ISO/IEC 646 (or ASCII), the C0 control code, the Universal Coded Character Set (or Unicode), and EBCDIC.
11223344) UNION SELECT NULL,NULL,NULL,NULL WHERE 1=2 –- No Error - Syntax is right.
A field with a NULL value is a field with no value. If a field in a table is optional, it is possible to insert a new record or update a record without adding a value to this
union all select null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null
In R language, NULL … Continue reading R null values: NULL, NA, NaN, Inf.