So I want to change a column in my SQL Server database to not allow nulls, but I keep getting an error. this is the sql statement I am using:
alter table [dbo].[mydatabase] alter column WeekInt int not null
and this is the error I am getting :
Msg 515, Level 16, State 2, Line 1
Cannot insert the value NULL into column 'WeekInt', table 'CustomerRadar.dbo.tblRWCampaignMessages'; column does not allow nulls. UPDATE fails.
The statement has been terminated.
I'm pretty sure my sql is right, and there are no nulls currently in the column I am trying to change so I am really not sure as to what is causing the problem. Any ideas? I'm stumped.
Clearly, the table has NULL values in it. Which you can check with:
select *
from mydatabase
where WeekInt is NULL;
Then, you can do one of two things. Either change the values:
update mydatabase
set WeekInt = -1
where WeekInt is null;
Or delete the offending rows:
delete from mydatabase
where WeekInt is null;
Then, when all the values are okay, you can do the alter table statement.
If you are trying to change a column to not null, and you are getting this error message, yet it appears the column has no nulls, ensure you are checking for is null and not = null (which gives different results).
Select * from ... where column is null
instead of
Select * from ... where column = null
I am adding this because it tripped me up and took a while to resolve.
This will work. You should send a default value, then it will change all the previous record to -1 in this example.
alter table [dbo].[mydatabase] alter column WeekInt int not null DEFAULT '-1';
Related
I have a problem that the new added column can't be used in the further comments.
I have a temp table built by "select into" then I need to add an identity column by "alter table". But when I want to use the new column in a "join", I got an error "Invalid column". please note that, these commands could work separately.
I think the reason is, the new column is not found by the compiler and it give an error before running it.
Is there a solution for that ?
I have got this problem in sql server 2000 and it seems in a newer version, the problem is not there.
create table #tmp_tb
(name varchar(4), val int)
insert into #tmp_tb values('ab',1);
insert into #tmp_tb values('abc',2);
select * from #tmp_tb
alter table #tmp_tb add id int NOT NULL IDENTITY(1,1);
select * from #tmp_tb
select id,name,val from #tmp_tb
An error occurred :
Msg 207, Level 16, State 3, Line 9
Invalid column name 'id'.
Replace the last line with
EXECUTE sp_executesql N'select id,name,val from #tmp_tb';
Indeed, the parser doesn't know about the new column yet. By passing it through sp_executesql you avoid this.
I code this query, but unfortunately, I got this error:
"Argument data type bit is invalid for argument 1 of substring
function."
My Stored Procedure is:
ALTER TABLE A ALTER COLUMN B nvarchar(20);
UPDATE A SET B = CASE WHEN SUBSTRING(B, 1, 2)>1000
THEN '1' + B ELSE B END
I convert my data but again get an error.
Absolutely my update query work if there is not the first one(Alter Table Alter Column).
Can anyone explaine why this occurred and how should I fix it?
This code works:
create table a (b bit);
alter table a alter column b nvarchar(20);
go
update a
set b = substring(b, 1, 2);
This code does not:
create procedure p as
begin
alter table a alter column b nvarchar(20);
update a
set b = substring(b, 1, 2);
end;
Why not? The first code actually changes the table, so the update is correct when it is run. Within the stored procedure, the two statements are compiled -- but not run. That means that the update is compiled, but the table has not changed. Hence you get an error.
Although you could solve this using dynamic SQL, I would instead ask why you are modifying column types in a stored procedure. That seems quite irregular. Normally, stored procedures do not do such modifications.
ALTER table Table_1
ALTER COLUMN Id NVARCHAR(20)
//Then continue...
Does anyone see what's wrong with this code for SQL Server?
IF NOT EXISTS(SELECT *
FROM sys.columns
WHERE Name = 'OPT_LOCK'
AND object_ID = Object_id('REP_DSGN_SEC_GRP_LNK'))
BEGIN
ALTER TABLE REP_DSGN_SEC_GRP_LNK
ADD OPT_LOCK NUMERIC(10, 0)
UPDATE REP_DSGN_SEC_GRP_LNK
SET OPT_LOCK = 0
ALTER TABLE REP_DSGN_SEC_GRP_LNK
ALTER COLUMN OPT_LOCK NUMERIC(10, 0) NOT NULL
END;
When I run this, I get:
Msg 207, Level 16, State 1, Line 3
Invalid column name 'OPT_LOCK'.
on the update command.
Thanks.
In this case you can avoid the problem by adding the column as NOT NULL and setting the values for existing rows in one statement as per my answer here.
More generally the problem is a parse/compile issue. SQL Server tries to compile all statements in the batch before executing any of the statements.
When a statement references a table that doesn't exist at all the statement is subject to deferred compilation. When the table already exists it throws an error if you reference a non existing column. The best way round this is to do the DDL in a different batch from the DML.
If a statement both references a non existing column in an existing table and a non existent table the error may or may not be thrown before compilation is deferred.
You can either submit it in separate batches (e.g. by using the batch separator GO in the client tools) or perform it in a child scope that is compiled separately by using EXEC or EXEC sp_executesql.
The first approach would require you to refactor your code as an IF ... cannot span batches.
IF NOT EXISTS(SELECT *
FROM sys.columns
WHERE Name = 'OPT_LOCK'
AND object_ID = Object_id('REP_DSGN_SEC_GRP_LNK'))
BEGIN
ALTER TABLE REP_DSGN_SEC_GRP_LNK
ADD OPT_LOCK NUMERIC(10, 0)
EXEC('UPDATE REP_DSGN_SEC_GRP_LNK SET OPT_LOCK = 0');
ALTER TABLE REP_DSGN_SEC_GRP_LNK
ALTER COLUMN OPT_LOCK NUMERIC(10, 0) NOT NULL
END;
The root cause of the error is the newly added column name is not reflected in the sys.syscolumns and sys.columns table until you restart SQL Server Management Studio.
For your information,you can replace the IF NOT EXISTS with the COL_LENGTH function. It takes two parameters,
Table Name and
Column you are searching for
If the Column is found then it returns the range of the datatype of the column Ex: Int (4 bytes), when not found then it returns a NULL.
So, you could use this as follows and also combine 3 Statements into one.
IF (SELECT COL_LENGTH('REP_DSGN_SEC_GRP_LNK','OPT_LOCK')) IS NULL
BEGIN
ALTER TABLE REP_DSGN_SEC_GRP_LNK
ADD OPT_LOCK NUMERIC(10, 0) NOT NULL DEFAULT 0
END;
Makes it simpler.
Given the following SQL:
IF EXISTS (SELECT * FROM sys.columns WHERE name = 'NewFieldName' AND object_id = OBJECT_ID('dbo.MyTableName'))
RETURN
-- Add NewFieldName column to part of the Summer 2012 release cycle.
ALTER TABLE dbo.[MyTableName] ADD
[NewFieldName] SmallINT NOT NULL
CONSTRAINT DF_MyTableName_NewFieldName DEFAULT (2)
UPDATE [MyTableName] SET NewFieldName = 1 WHERE [Name] = 'FindMe' --Update one specific value
Produces the following error message:
Msg 207, Level 16, State 1, Line 10 Invalid column name
'NewFieldName'.
I'm sure I'm missing something basic, but trying to put "GO" after the alter makes the UPDATE run everytime and I don't want to do that.
How can I structure this statement so that it will check to see if the column exists and, if it doesn't add it and then set the values as stated in my UPDATE statements?
You need the statement referencing the new column to be compiled after the new column is added. One way of doing this is to run it as a child batch with EXEC.
IF NOT EXISTS (SELECT *
FROM sys.columns
WHERE name = 'NewFieldName'
AND object_id = OBJECT_ID('dbo.MyTableName'))
BEGIN
-- Add NewFieldName column to part of the Summer 2012 release cycle.
ALTER TABLE dbo.[MyTableName]
ADD [NewFieldName] SMALLINT NOT NULL
CONSTRAINT DF_MyTableName_NewFieldName DEFAULT (2)
EXEC(' UPDATE [MyTableName] SET NewFieldName = 1 WHERE [Name] = ''FindMe''')
END
The reason it worked for you originally is presumably because the table itself did not exist when the batch was compiled thus meaning that all statements in it referencing the table are subject to deferred compile.
How can I create a sequence on a table so that it goes from 0 -> Max value?
I've tried using the following SQL code, but it does not insert any values into the table that I am using:
CREATE SEQUENCE rid_seq;
ALTER TABLE test ADD COLUMN rid INTEGER;
ALTER TABLE test ALTER COLUMN rid SET DEFAULT nextval('rid_seq');
The table I am trying to insert the sequence in is the output from another query. I can't figure out if it makes more sense to add the sequence during this initial query, or to add the sequence to the table after the query is performed.
Set the default value when you add the new column:
create sequence rid_seq;
alter table test add column rid integer default nextval('rid_seq');
Altering the default value for existing columns does not change existing data because the database has no way of knowing which values should be changed; there is no "this column has the default value" flag on column values, there's just the default value (originally NULL since you didn't specify anything else) and the current value (also NULL) but way to tell the difference between "NULL because it is the default" and "NULL because it was explicitly set to NULL". So, when you do it in two steps:
Add column.
Change default value.
PostgreSQL won't apply the default value to the column you just added. However, if you add the column and supply the default value at the same time then PostgreSQL does know which rows have the default value (all of them) so it can supply values as the column is added.
By the way, you probably want a NOT NULL on that column too:
create sequence rid_seq;
alter table test add column rid integer not null default nextval('rid_seq');
And, as a_horse_with_no_name notes, if you only intend to use rid_seq for your test.rid column then you might want to set its owner column to test.rid so that the sequence will be dropped if the column is removed:
alter sequence rid_seq owned by test.rid;
In PostgreSQL:
UPDATE your_table SET your_column = nextval('your_sequence')
WHERE your_column IS NULL;
I'm not fluent in postgresql so I'm not familiar with the "CREATE SEQUENCE" statement. I would think, though, that you're adding the column definition correctly. However, adding the column doesn't automatically insert data for existing rows. A DEFAULT constraint is for new rows. Try adding something like this afterwards to populate data on the existing rows.
DECLARE #i Int
SET #i = 0
SET ROWCOUNT 1
WHILE EXISTS (SELECT 1 FROM test WHERE rid IS NULL) BEGIN
UPDATE test SET rid = #i WHERE rid IS NULL
END
SET ROWCOUNT 0