A SAMPLE table has only one column ID of type int, default null.
In Oracle when I do:
insert into SAMPLE (ID) values ('');
the new record is added with blank value. But in SQL Server 2008, when I run the same insert statement, the new record has the value of 0.
Is there a way to force SQL Server 2008 to default blank string to NULL instead of 0 (for numerical type of columns)?
Assuming that your INSERT statement is part of a stored procedure re-used in many places of your application (or, perhaps, is a batch always constructed by the same part of the client code) and that the inserted value is a number passed as a string argument, you could modify the INSERT like this:
INSERT INTO SAMPLE (ID) VALUES (NULLIF(#argument, ''));
Use NULL instead.
insert into SAMPLE (ID) values (NULL);
How about another idea - define an INSTEAD OF INSERT Trigger.
Despite the fact that you're trying to insert a string, with this the operation is "intercepted", empty string is replaced by NULL, and the insert succeeds.
If you define this trigger on your table, then you can continue to insert empty string as before, with no other changes.
Edit: As Martin Smith points out, this effectively is a comparison to 0 (the equivalent of empty string as an int) meaning you won't be able to store 0 in this table. I leave this answer here in case that's acceptable to your situation - either that or re-do all your queries!
CREATE TRIGGER EmptyStringTrigger
ON [SAMPLE]
INSTEAD OF INSERT
AS
BEGIN
INSERT INTO [SAMPLE](ID)
SELECT CASE
WHEN ID = '' THEN NULL
ELSE ID
END
FROM inserted
END
SQL Fiddle example
You can't insert a 'string' into a int column. Oracle must be just handling that for you.
Just try inserting NULL if that's what you need.
insert into SAMPLE (ID) values (NULL);
One more option
insert into SAMPLE (ID) values (DEFAULT)
Related
For example, I have a column with type int.
The raw data source has integer values, but the null values, instead of being empty (''), is 'NIL'
How would I handle those values when trying to Bulk Insert into MSSQL?
My code is
create table test (nid INT);
bulk insert test from #FILEPATH with (format="CSV", firstrow=2);
the first 5 rows of my .csv file looks like
1
2
3
NIL
7
You can replace the nil with " (empty string) directly in your data source file or insert the data into a staging table and transform it:
BULK INSERT staging_sample_data
FROM '\\data\sample_data.dat';
INSERT INTO [sample_data]
SELECT NULLIF(ColA, 'nil'), NULLIF(ColB, 'nil'),...
Of course if your field is for example a numeric, the staging table should have a string field. Then, you can do as Larnu offers: 'TRY_CONVERT(INT, ColA)'.
*Note: if there are default constraints you may need to check how to keep nulls
This seems like a trivial question. And it is. But I have googled for over a day now, and still no answer:
I wish to do a bulk insert where for a column whose datatype is varchar(100), I wish to insert an empty string. Not Null but empty. For example for the table:
create table temp(columnName varchar(100))
I wish to insert an empty string as the value:
BULK INSERT sandbox..temp FROM
'file.txt' WITH ( FIELDTERMINATOR = '|#', ROWTERMINATOR = '|:' );
And the file contents would be row1|:row2|:|:|:. So it contains 4 rows where last two rows are intended to be empty string. But they get inserted as NULL.
This question is not the same as the duplicate marked question: In a column, I wish to have the capacity to insert both: NULL and also empty-string. The answer's provided does only one of them but not both.
Well instead of inserting empty string explicitly like this why not let your table column have a default value of empty string and in your bulk insert don't pass any values for those columns. Something like
create table temp(columnName varchar(100) default '')
I tried to insert some rows into SQL server database and throws an error:
Conversion failed when converting the varchar value 'null' to data type bit
Could anyone explain what is this for?
This is not in a program.
What you might be trying
INSERT INTO TESTTABLE(BITCOLUMN) VALUES('NULL')
What should it actually be..
INSERT INTO TESTTABLE(BITCOLUMN) VALUES(NULL)
If you want to insert a null value into a column, you need to write NULL, and not 'NULL' (wrapping it in quotes indicates that it is a VARCHAR containing the letters N, U, L L - not a null value).
That is what the error message is telling you: you're trying to insert the VARCHAR value 'NULL' into a column that will only accept bit data.
Change the 'NULL' in your insert query to NULL.
You need something like this:
INSERT INTO TableName(ColumnName) VALUES(NULL); --this is the right way
Instead of this:
INSERT INTO TableName(ColumnName) VALUES('NULL'); --this is the wrong way
I'm new to firebird and I have verious issues. I want to insert various lines into a table selected from another table.
Here's the code:
/*CREATE GENERATOR POS; */
SET GENERATOR POS TO 1;
SET TERM ^;
create trigger BAS_pkassign
for MATERIAL
active before insert position 66
EXECUTE BLOCK
AS
declare posid bigint;
select gen_id(POS, 1)
from RDB$DATABASE
into :posid;
BEGIN
END
SET TERM ; ^
INSERT INTO MATERIAL ( /*ID */ LOCATION, POSID, ARTID, ARTIDCONT, QUANTITY )
SELECT 1000, ':posid', 309, BAS_ART.ID, 1
FROM BAS_ART
WHERE BAS_ART.ARTCATEGORY LIKE '%MyWord%'
The ID should autoincrement from 66 on. The posid should autoincrement from 1 on.
Actually it is not inserting anything.
I'm using Firebird Maestro and have just opened the SQL Script Editor (which doesnt throw any error message on executing the script).
Can anybody help me?
Thanks!
Additional information:
The trigger should autoincrement the column "ID" - but I dont know how exactly I can change it so it works.. The ':posid' throws an error using it :posid but like this theres no error (I guess its interpretated as a string). But how do I use it right?
I dont get errors when I execute it. The table structure is easy. I have 2 tables:
1.
Material (
ID (INTEGER),
Location (INTEGER),
POSID (INTEGER),
ARTID (INTEGER),
ARTIDCONT (INTEGER),
QUANTITY (INTEGER),
OTHERCOLUMN (INTEGER))
and the 2. other table
BAS_ART (ID (INTEGER), ARTCATEGORY (VARCHAR255))
-> I want to insert all entries from the table BAS_ART which contain "MyWord" in the column ARTCATEGORY into the MATERIAL table.
I don't understand why you need the trigger at all.
This problem:
I want to insert all entries from the table BAS_ART which contain "MyWord" into the MATERIAL table
Can be solved with a single insert ... select statement.
insert into material (id, location, posid, artid, quantity)
select next value for seq_mat_id, 1000, next value for seq_pos, id, 1
from bas_art
where artcategory = 'My Word';
This assumes that there is a second sequence (aka "generator") that is named seq_mat_id that provides the new id for the column material.id
For most of my answer I will assume a very simple table:
CREATE TABLE MyTable (
ID BIGINT PRIMARY KEY,
SomeValue VARCHAR(255),
posid INTEGER
)
Auto-increment identifier
Firebird (up to version 2.5) does not have an identity column type (this will be added in Firebird 3), instead you need to use a sequence (aka generator) and a trigger to get this.
Sequence
First you need to create a sequence using CREATE SEQUENCE:
CREATE SEQUENCE seqMyTable
A sequence is atomic which means interleaving transactions/connections will not get duplicate values, it is also outside transaction control, which means that a ROLLBACK will not revert to the previous value. In most uses a sequences should always increase, so the value reset you do at the start of your question is wrong for almost all purposes; for example another connection could reset the sequence as well midway in your execution leaving you with unintended duplicates of POSID.
Trigger
To generate a value for an auto-increment identifier, you need to use a BEFORE INSERT TRIGGER that assigns a generated value to the - in this example - ID column.
CREATE TRIGGER trgMyTableAutoIncrement FOR MyTable
ACTIVE BEFORE INSERT POSITION 0
AS
BEGIN
NEW.ID = NEXT VALUE FOR seqMyTable;
END
In this example I always assign a generated value, other examples assign a generated value only when the ID is NULL.
Getting the value
To get the generated value you can use the RETURNING-clause of the INSERT-statement:
INSERT INTO MyTable (SomeValue) VALUES ('abc') RETURNING ID
INSERT INTO ... SELECT
Using INSERT INTO ... SELECT you can select rows from one table and insert them into others. The reason it doesn't work for you is because you are trying to assign the string value ':pos' to a column of type INTEGER, and that is not allowed.
Assuming I have another table MyOtherTable with a similar structure as MyTable I can transfer values using:
INSERT INTO MyTable (SomeValue)
SELECT SomeOtherValue
FROM MyOtherTable
Using INSERT INTO ... SELECT it is not possible to obtain the generated values unless only a single row was inserted.
Guesswork with regard to POSID
It is not clear to me what POSID is supposed to be, and what values it should have. It looks like you want to have an increasing value starting at 1 for a single INSERT INTO ... SELECT. In versions of Firebird up to 2.5 that is not possible in this way (in Firebird 3 you would be able to use ROW_NUMBER() for this).
If my guess is right, then you will need to use an EXECUTE BLOCK (or a stored procedure) to assign and increase the value for every row to be inserted.
The execute block would be something like:
EXECUTE BLOCK
AS
DECLARE posid INTEGER = 1;
DECLARE someothervalue VARCHAR(255);
BEGIN
FOR SELECT SomeOtherValue FROM MyOtherTable INTO :someothervalue DO
BEGIN
INSERT INTO MyTable (SomeValue, posid) VALUES (:someothervalue, :posid);
posid = posid + 1;
END
END
Without an ORDER BY with the SELECT the value of posid is essentially meaningless, because there is no guaranteed order.
I have a sql server nvarchar field with a "Default Value or Binding" of empty string. It also happens to be a not null field.
Does this mean that there is no default or that it is a default of a string with no characters in it.
If I don't insert a value, will it insert with an empty string or fail with a "not null" error?
The default is a blank (empty) string.
If you don't provide a value, the insert will be successful and the value will be blank, not null.
Its the same as (assuming data is the col in question):
create table #t (id int, data varchar(100) not null default(''))
So:
insert into #t (id) values (1)
insert into #t (id,data) values (2,default)
insert into #t (id,data) values (3, 'allowed')
select * from #t
will return
1
2
3 allowed
and ..
insert into #t (id,data) values (1, null)
-- will error
If you have a true empty string as a default, then it will autopopulate with a 0 length string.
You should be careful to ensure it is a 0 length string and not nothing though. If for instance you are looking in the table builder gui for SSMS and it shows a blank for "Default Value or Binding", that means that there is no default value and an insert will fail if it is not populated. If you want it to have a 0 length string, populate it with '' (two single-quotes together with nothing in between.)
Default value for a column is just that - sql server will put that value when you dont supply one for the column. The value in the column will be an empty string. Not null error will not happen