Question

I have a pipe delimited file with some NULL date fields. I load this data into a temp table with default values for NULL dates. In my case, I wish to default to 1950-01-01. However, these defaults are seemingly being overwritten and 0000-00-00 is being inserted. Here is a quick bash script I wrote to test:

#!/bin/bash

CMD="CREATE TEMPORARY TABLE IF NOT EXISTS ar_tmp LIKE ar; LOAD DATA INFILE '/some/path/ar.txt' INTO TABLE ar_tmp FIELDS TERMINATED BY '|'; SELECT * FROM ar_tmp;"

mysql -uuser -ppassword db -e "$CMD" > /opt/rxdb/tmp.log

I have grepped my source file and confirmed the expected NULL dates have \N and no where in the file is the pattern 0000-00-00.

Here is the structure of ar_tmp:

Field                   Type            Null    Key     Default Extra
customer_code           int(11)         NO      PRI     0
activity_date           date            NO      PRI     1950-01-01
delivery_date           date            NO      PRI     1950-01-01
sequence                int(11)         NO      PRI     0
type                    varchar(10)     YES             NULL
due_date                date            YES             1950-01-01
original_charge         float           YES             NULL
prior_alloc             float           YES             NULL
current_alloc           float           YES             NULL
future_alloc            float           YES             NULL
open_balance            float           YES             NULL
shipto_customer         int(11)         NO      MUL     0
reference               varchar(10)     YES             NULL
journal_ref_number      int(11)         YES             NULL
next_month_flag         int(11)         YES             NULL
journal_type            varchar(15)     YES             NULL
activity_num            int(11)         YES             NULL
document_path           varchar(100)    YES             NULL
conditional_eft_approved char(1)        NO              N
customer_name           varchar(30)     YES             NULL
allow_web_payment       char(1)         YES             NULL
modify_date             datetime        NO              1950-01-01 12:00:00

The defaults being over road are activity_date, delivery_date and due_date. Can someone explain what is going on?

EDIT:

Three lines from the source file:

5830|2012-02-21|\N|29543|PAYMENT|\N|-600.5|0|0|0|-600.5|5830|505700|4807|0|Cash|0||N|TIME WARNE|N|2012-03-09 07:07:11
8057|2012-03-08|\N|32523|PAYMENT|\N|-1348.74|0|-1348.74|0|0|8057|1486|22|0|Cash|0||N|PACIFIC HA|N|2012-03-09 07:07:11
8103|2012-03-07|\N|32138|PAYMENT|\N|-1382.29|0|-1382.29|0|0|8103|3719|4|0|Cash|0||N|NORTH COUN|N|2012-03-09 07:07:11

Corresponding resultant records:

5830    2012-02-21      0000-00-00      29543   PAYMENT NULL    -600.5  0       0       0       -600.5  5830    505700  4807    0       Cash    0               N       TIME WARNE      N       2012-03-09 07:07:11
8057    2012-03-08      0000-00-00      32523   PAYMENT NULL    -1348.74        0       -1348.74        0       0       8057    1486    22      0       Cash    0               N       PACIFIC HA      N       2012-03-09 07:07:11
8103    2012-03-07      0000-00-00      32138   PAYMENT NULL    -1382.29        0       -1382.29        0       0       8103    3719    4       0       Cash    0               N       NORTH COUN      N       2012-03-09 07:07:11

Answer 1

If \N is being transformed into an empty string, then the INSERT command will use it, and the DEFAULT value will be ignored.

I mean with this:

INSERT INTO table(customer, date) VALUES ("123", "")

then date will contain 0000-00-00. For the default value to be used, nothing should be passed for the date at all:

INSERT INTO table(customer) VALUES ("123")