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.
coding style - SQL - Select null as FIELDNAME? - Stack Overflow
I have come across some code that says … What exactly is this doing? Is it getting the field names unitcost and markup? Why would you use "select null as..."? New to this sorry. Thanks.
999999.9' /**/union/**/all /**/select /**/cast...
Ref: 999999.9' union all select 99,2 and '0'='0.
999999.9 /**/union/**/all /**/select /**/cast...
Best Result For : 999999.9 uNiOn aLl sElEcT cAsT 0x393133353134353632312e39 as char --. تفسير فرط السبحة في المنام.
SQL NULL Values - IS NULL and IS NOT NULL
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 field.
Null character - Wikipedia
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.
3) union all select null, null, null, null, null, null, null, null, null, null...
After looking through the whole database as well as the files on the site, I'm nearly 99% positive nothing was harmed, deleted or changed. Which makes me glad to know that I'm knowledgeable enough in my php to know how to prevent these things.
sql injection "union select null" - CodeProject | To display as
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...