If I have the table … This will display Firstname-Middlename-Surname e.g. … The second one (Jane’s) displays correct, however since John doesn’t have a middlename, I want it to ignore the second dash.
mysql> SELECT NULL, 1+NULL, CONCAT('Invisible',NULL); To search for column values that are NULL, you cannot use an expr = NULL test. The following statement returns no rows, because expr = NULL is never true for any expression: Press CTRL+C to copy. mysql> SELECT * FROM my_table...
1 UNION ALL SELECT NULL,concat(0x28,column1,0x3a,column2,0x29) FROM database2.table1--. Error Based.
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...
If I have this - tadd is the Address table: … Is there a way to exclude the apt_number if it doesn't exist? I was thinking of: … But it will return only those rows with apt_number...
SELECT * FROM members WHERE username = 'admin'--' AND password = 'password' This is going to log
> select f.name, group_concat(quality) quality, sum(fs.quantity) quantity, sum(fp.price*fs.quantity) price from (select * from fruits where name = 'apple') as f, fruitstock as fs
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.
SQL’s NULL indicates absent data. NULL propagates through expressions and needs distinct comparison operators.