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.
Then in the second table I have select ..., null as opt from... I know that I could have an empty string with '' as
How can I run a MySQL query that selects everything that is not null? It would be something like … Do I just remove the all and go..?
I'm querying the back-end of an application. For what ever reason the developer decided to use NVARCHAR for all fields. I'm having a problem with one of the "date" fields--somehow it got populated...
I understand that a char variable can accept a null character(1 byte) i.e; \0 as its value but, I don't understand how a char variable in my application below accepts a pointer(4 bytes)...
Note: not a NULL field value, but the null character (see link). I have a column with a mix of typical and a null character.
Note: A NULL value is different from a zero value or a field that contains spaces.
> char array[SIZE] = {0}; Nothing wrong with this. It just assumes that the remaining SIZE-1 elements are also zero, so that's it, job done.
The null character (also null terminator or null byte), abbreviated NUL or NULL, is a control character with the value zero. It is present in many character sets, including ISO/IEC 646 (or ASCII)...
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...