Load NULL values INT - mysql

Question

FIY:
I'm working with a CVS file from Census - FactFinder
Using MySQL 5.7
OS is Windows 10 PRO
So, I created this table:
+----------+------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+------------+------+-----+---------+-------+
| SERIALNO | bigint(13) | NO | PRI | NULL | |
| DIVISION | int(9) | YES | | NULL | |
| PUMA | int(4) | YES | | NULL | |
| REGION | int(1) | YES | | NULL | |
| ST | int(1) | YES | | NULL | |
| ADJHSG | int(7) | YES | | NULL | |
| ADJINC | int(7) | YES | | NULL | |
| FINCP | int(6) | YES | | NULL | |
| HINCP | int(6) | YES | | NULL | |
| R60 | int(1) | YES | | NULL | |
| R65 | int(1) | YES | | NULL | |
+----------+------------+------+-----+---------+-------+
And tried to load data using:
LOAD DATA INFILE "C:/ProgramData/MySQL/MySQL Server 5.7/Uploads/Housing_Illinois.csv"
INTO TABLE housing
CHARACTER SET latin1
COLUMNS TERMINATED BY ','
LINES TERMINATED BY '\n'
It didn`t work as this message appear:
ERROR 1366 (HY000): Incorrect integer value: '' for column 'FINCP' at
row 2
The row the error message is referring to is:
2012000000051,3,104,2,17,1045360,1056030,,8200,1,1
I believed FINCP which is the blank value ,, right before 8200 is the problem. So I followed this thread instructions: MySQL load NULL values from CSV data
And updated my code to:
LOAD DATA INFILE "C:/ProgramData/MySQL/MySQL Server 5.7/Uploads/Housing_Illinois.csv"
INTO TABLE housing
CHARACTER SET latin1
COLUMNS TERMINATED BY ','
LINES TERMINATED BY '\n'
(#SERIALNO, #DIVISION, #PUMA, #REGION, #ST, #ADJHSG, #ADJINC, #FINCP, #HINCP, #R60, #R65)
SET
SERIALNO = nullif(#SERIALNO,''),
DIVISION = nullif(#DIVISION,''),
PUMA = nullif(#PUMA,''),
REGION = nullif(#REGION,''),
ST = nullif(#ST,''),
ADJHSG = nullif(#ADJHSG,''),
ADJINC = nullif(#ADJINC,''),
FINCP = nullif(#FINCP,''),
HINCP = nullif(#HINCP,''),
R60 = nullif(#R60,''),
R65 = nullif(#R65,'');
The first error is now gone but this message appears:
' for column 'R65' at row 12t integer value: '
The row at which this message is referring to is:
2012000000318,3,1602,2,17,1045360,1056030,,,,
There's no error message so I don't know what exactly is the problem. I can only assume that the problem is that there are four consecutive blank values.
Another tip, if I use CSV and change all blank to 0 the code goes smoothly, but I`m not a fan or editing raw data so I would like to know other options.
Bottom line, I have two questions:
Shouldn`t data be loaded with the first code as MySQL should take ,, as null and 0 a plain 0?
What's the problem I'm getting now that I'm using SERIALNO = nullif(#SERIALNO,'')
I want to be able to differentiate between 0 and null/blank values.
Thank you.

Answer 1

MySQL's LOAD DATA tool interprets \N as being a NULL value. So, if your troubled row looked like this:
2012000000318,3,1602,2,17,1045360,1056030,\N,\N,\N,\N
then you might not have this problem. If you have access to a regex replacement tool, you may try searching for the following pattern:
(?<=^)(?=,)|(?<=,)(?=,)|(?<=,)(?=$)
Then, replace with \N. This should fill in all the empty slots with \N, which semantically will be interpreted by MySQL as meaning NULL. Note that if you were to write a table out from MySQL, then nulls would be replaced with \N. The issue is that your data source and MySQL don't know about each other.