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 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.
What is the difference between … and … and why does the latter not work?
I ran into code similar to this today. … It seems to imply that data type information can be associated with a NULL value. Does this attach metadata to the NULL value identifying it as the specified data...
Note: A NULL value is different from a zero value or a field that contains spaces.
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...
R language supports several null-able values and it is relatively important to understand how these