I'm trying to run the following SQL statement:
IF OBJECT_ID('MyTable') IS NOT NULL
DROP TABLE MyTable
SELECT
a.UserId
INTO
MyTable
FROM
UsersTable a
WHERE
a.UserId='12359670-1DC9-4A0A-8AE5-29B664C1A57E'
ALTER TABLE MyTable ALTER COLUMN UserId UNIQUEIDENTIFIER NOT NULL
ALTER TABLE MyTable ADD PRIMARY KEY(UserId)
However, I get the following error:
Cannot define PRIMARY KEY constraint on nullable column in table 'MyTable'.
Any ideas?
This assumes SQL Server based on UNIQUEIDENTIFIER
Put a GO between (or relevant batch separator if not SQL Server)
....
ALTER TABLE MyTable ALTER COLUMN UserId UNIQUEIDENTIFIER NOT NULL
GO
ALTER TABLE MyTable ADD PRIMARY KEY(UserId)
At batch compile time, the column is nullable. So break up the batches.
SQL isn't a line by line procedural language
You'll have to do this in a stored procedure
ALTER TABLE MyTable ALTER COLUMN UserId UNIQUEIDENTIFIER NOT NULL
EXEC('ALTER TABLE MyTable ADD PRIMARY KEY(UserId)')
Found a solution.
I'm using the following statement:
EXEC sp_ExecuteSQL N'ALTER TABLE MyTable ALTER COLUMN UserId UNIQUEIDENTIFIER NOT NULL'
EXEC sp_ExecuteSQL N'ALTER TABLE MyTable ADD PRIMARY KEY(UserId)'
You don't need dynamic SQL. Just create the table and the key first.
CREATE TABLE MyTable (UserId UNIQUEIDENTIFIER NOT NULL PRIMARY KEY);
INSERT INTO MyTable (UserId)
SELECT UserId
FROM UsersTable
WHERE UserId='12359670-1DC9-4A0A-8AE5-29B664C1A57E';
Related
I want to add a primary key constraint to an existing column on an existing table that contains data. The column is not nullable.
However, when I call
alter table mytable add primary key (mycolumn)
I get an 8111:
Msg 8111, Level 16, State 1, Line 2 Cannot define PRIMARY KEY
constraint on nullable column in table 'mytable'
Even if I call both instructions in a row:
alter table mytable alter column mycolumn INT NOT NULL;
alter table mytable add primary key (mycolumn)
I still get an 8111
- and the column description in SQL Server Management Studio confirms, that mycolumn is set to NOT NULL
What can I do this?
You need to separate your batches. It would be best to include the schema name as well.
alter table dbo.mytable alter column mycolumn INT NOT NULL;
go
alter table dbo.mytable add primary key (mycolumn);
rextester demo: http://rextester.com/TZLEWP56616
Its about ORACLE (PL/SQL) script. I am not very familiar with databse to be honest.
I want to alter the length of a string in a column from 30 to 60. It is not null column.
If the table is empty and I run following script then it works:
alter table [TABLE_NAME] add ( NEW_COLUMN NVARCHAR2(60) DEFAULT 'null' NOT NULL );
/
alter table [TABLE_NAME] DROP CONSTRAINT PK_[TABLE_NAME];
/
begin
for rec in ( select * from [TABLE_NAME] )
loop
update [TABLE_NAME] set NEW_COLUMN =rec.OLD_COLUMN where Name_ID=rec.Name_ID;
end loop;
end;
/
alter table [TABLE_NAME] drop column OLD_COLUMN;
/
alter table [TABLE_NAME] rename column NEW_COLUMN to OLD_COLUMN;
/
alter table [TABLE_NAME] add CONSTRAINT PK_[TABLE_NAME] PRIMARY KEY(Name_ID);
/
But if the table has values then this script does not work.
It gives error: Cannot drop constraint - nonexistent constraint
However, if I remove lines about constraints (second and second last) then it works.
Now I don’t know if the table will be empty or it will have data so I need a script that can work in both the situations. Can anyone help please?
Following script for creating table:
CREATE TABLE TABLE_NAME
(
Name_ID NVARCHAR2(7) NOT NULL,
OLD_COLUMN NVARCHAR2(30) NOT NULL,
CONSTRAINT PK_TABLE_NAME PRIMARY KEY(Name_ID, OLD_COLUMN)
)
/
So while creating table it puts the primary key constraints but while updating table it drops this constraints somehow. I am simplyfying the sitation here. The tables are updates through java code. What I need to do is make a script that work in both situations - with data or just after creating table and modifying the column.
The following script works for me, regardless of whether the insert statement is present or not (ie. the table has or has not data):
CREATE TABLE TABLE_NAME
(
Name_ID NVARCHAR2(7) NOT NULL,
OLD_COLUMN NVARCHAR2(30) NOT NULL,
CONSTRAINT PK_TABLE_NAME PRIMARY KEY(Name_ID, OLD_COLUMN)
);
insert into table_name (name_id, old_column)
values ('test', 'test_old_col');
commit;
alter table table_name add (new_column nvarchar2(60) default 'null' not null);
update table_name set new_column = old_column;
commit;
alter table table_name drop constraint PK_TABLE_NAME;
alter table table_name drop column old_column;
alter table table_name rename column new_column to old_column;
alter table TABLE_NAME add CONSTRAINT PK_TABLE_NAME PRIMARY KEY(Name_ID, old_column);
drop table table_name;
I have assumed that you meant to recreate the primary key with the old_column in it, otherwise you would be unable to recreate it if there are any duplicate values present in the name_id column.
As an alternative, you can save the old data and create a new table with new parameters. Then insert the old values.
In SQL Server Management Studio:
"your database" => task => generatescripts => select specific database object => "your table" => advanced => types of data to script - schema and data => generate
I have a table dbo.ExceptionMessage and now I want to change the column datatype nvarchar(100) to nvarchar(MAX). I used alter query for changing this
ALTER TABLE dbo.ExceptionMessage ALTER COLUMN Address nvarchar(MAX)
and while excecuting this query it shows some error like.
The object 'DF_ExceptionMessage_Address' is dependent on column 'Address'.
ALTER TABLE ALTER COLUMN Address failed because one or more objects access this column.
How can we solve this...
First Delete all Constraint Like this
ALTER TABLE TableName DROP CONSTRAINT [DF__TableName__ColumnName__FieldName]
and then perform change
ALTER TABLE dbo.ExceptionMessage ALTER COLUMN Address nvarchar(MAX)
then re enter the constraints
You have to find out which type of constraint DF_ExceptionMessage_Address is, drop it, alter the column type and then re-create the constraint if you need it.
you try first:
ALTER TABLE <tablename> DROP CONSTRAINT <Con_Name>;
And Then Do your Alter
ALTER TABLE dbo.ExceptionMessage ALTER COLUMN Address nvarchar(MAX)
Again Add Constraint
thiz help you to alter
alter table TableName
alter column ColumnName nvarchar(200);
How to drop a Particular column in a Table?
CREATE TABLE dbo.MyTable (column_a INT, column_b VARCHAR(20) NULL);
GO
ALTER TABLE dbo.MyTable DROP COLUMN column_b;
GO
EXEC sp_help MyTable;
GO
DROP TABLE dbo.MyTable;
GO
I have created a foreign key (in SQL Server) by:
alter table company add CountryID varchar(3);
alter table company add constraint Company_CountryID_FK foreign key(CountryID)
references Country;
I then run this query:
alter table company drop column CountryID;
and I get this error:
Msg 5074, Level 16, State 4, Line 2
The object 'Company_CountryID_FK' is dependent on column 'CountryID'.
Msg 4922, Level 16, State 9, Line 2
ALTER TABLE DROP COLUMN CountryID failed because one or more objects access this column
I have tried this, yet it does not seem to work:
alter table company drop foreign key Company_CountryID_FK;
alter table company drop column CountryID;
What do I need to do to drop the CountryID column?
Thanks.
Try
alter table company drop constraint Company_CountryID_FK
alter table company drop column CountryID
This will work:
ALTER TABLE [dbo].[company] DROP CONSTRAINT [Company_CountryID_FK]
I think this will helpful to you...
DECLARE #ConstraintName nvarchar(200)
SELECT
#ConstraintName = KCU.CONSTRAINT_NAME
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS AS RC
INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS KCU
ON KCU.CONSTRAINT_CATALOG = RC.CONSTRAINT_CATALOG
AND KCU.CONSTRAINT_SCHEMA = RC.CONSTRAINT_SCHEMA
AND KCU.CONSTRAINT_NAME = RC.CONSTRAINT_NAME
WHERE
KCU.TABLE_NAME = 'TABLE_NAME' AND
KCU.COLUMN_NAME = 'TABLE_COLUMN_NAME'
IF #ConstraintName IS NOT NULL EXEC('alter table TABLE_NAME drop CONSTRAINT ' + #ConstraintName)
It will delete foreign Key Constraint based on specific table and column.
First check of existence of the constraint then drop it.
if exists (select 1 from sys.objects where name = 'Company_CountryID_FK' and type='F')
begin
alter table company drop constraint Company_CountryID_FK
end
alter table company drop constraint Company_CountryID_FK
I don't know MSSQL but would it not be:
alter table company drop **constraint** Company_CountryID_FK;
You can also Right Click on the table, choose modify, then go to the attribute, right click on it, and choose drop primary key.
Are you trying to drop the FK constraint or the column itself?
To drop the constraint:
alter table company drop constraint Company_CountryID_FK
You won't be able to drop the column until you drop the constraint.