Migration oracle to SQL server - null vs empty

Question

0.00/5 (No votes)

See more:

We have converted Oracle database to SQL server database. We are facing issue with null vs blank.

Scenario:

In oracle:

Create table Student (Sno int, FName varchar(20) not null, MName varchar(30) null,
Lname varchar(20) not null)

Insert into Student(Sno,Fname,Mname,Lname) values (10,'James' ,'','Clark')

Record Inserting into Oracle as Middle name inserting as null even we passed blank value('')
10,James,null,Clark

Record Inserting into SQL Server as Middle name inserting as blank in SQL server (showing empty space in the table, even we have the default constraint)
10,James,,Clark

we want to handle when blank ('') inserting into SQL table it should be treated as 'null' which is the similar behavior of Oracle database.

What I have tried:

for some existing triggers added condition nullif. but some of the table we don't have triggers and how to handle those tables when insert or update happening.

Posted 16-Jun-18 7:19am

sreenivasaraok

Updated 17-Jun-18 1:55am

Add a Solution

Comments

[no name] 16-Jun-18 13:22pm

I would say MSSQL is right. Empty string is _not_ NULL ;)
Insert into Student(Sno,Fname,Mname,Lname) values (10,'James' ,NULL,'Clark') is the correct way

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Kornfeld Eliyahu Peter · Answer 1 · 2018-06-17T01:56:00

It is a known Oracle problem (well that's a point of view, but SQL-92 disagrees with Oracle, but Oracle says he was here first)...
Oracle threat empty string as NULL value (it is an internal conversation).
I would not advise to force SQL to threat empty string as Oracle does for two reasons:
1. ANSI SQL says Oracle wrong
2. It will became a performance with large number of inserts with string variables
However if you can not skip one of these:
1. use triggers
2. wrap insert in SQL
3. change INSERT code in application