Possible Duplicate:
DEFAULT clause in ALTER TABLE statement resulting in syntax error
I am trying to execute the following statement using a SQL query within MS Access;
ALTER TABLE [table] ALTER COLUMN [column] SET DEFAULT 'default value'
However, I get a dialog displaying the error Syntax error in ALTER TABLE statement.
And when I click OK it highlights the word DEFAULT. I also tried the following statement;
ALTER TABLE [table]
ADD CONSTRAINT [Default] DEFAULT 'default value' FOR [column]
And I get another error Syntax error in CONSTRAINT clause.
What is the correct syntax for setting a default value in MS Access? The db file is Access 2003 format.
Support for DEFAULT was included in Access DDL with Jet 4 (Access 2000). However it can only be used in DDL executed from an ADO connection.
This worked with Access 2007.
CurrentProject.Connection.Execute "ALTER TABLE MyTable " & _
"ALTER COLUMN field2 SET DEFAULT ""foo"";"
Note if your db file is Access 97 or earlier, you won't be able to set a field DEFAULT value from DDL.
It seems, there would be Constraint issue with your column. Although following DDL statement is the correct way.
ALTER TABLE Persons ALTER COLUMN City SET DEFAULT 'SANDNES'
Reference
Related
I am having problems with some of my SQL scripts on SQL SERVER, indeed I am trying to transfer data from a column A to a column B of the same table and then drop the column B,
However my problem is that I have to check for the existence of A beforehand because the code is meant to be executed on a server where I don't have access (I work as a third party developper on a professionnal app)
Here is my code:
-- Export the data from the column name
-- Drop the column name
USE p_mynacellelocation_db_ChecklistWPF
GO
IF COL_LENGTH('model_trolley_part','name') IS NOT NULL
BEGIN
UPDATE model_trolley_part
SET name_en=[name];
ALTER TABLE model_trolley_part
DROP COLUMN [name];
END
In the case of the column name being non existent I would like not to do anything
However on execution of the code in a database where the column name is non existent SQL Server returns me:
Msg 207, Level 16, State 1, Line 12 Invalid column name 'name'.
Instead of jumping through all these hoops simply rename your original column.
https://learn.microsoft.com/en-us/sql/relational-databases/system-stored-procedures/sp-rename-transact-sql?view=sql-server-2017
exec sp_rename 'model_trolley_part.name', 'name_en', 'COLUMN'
You need to use dynamic SQL for this. The reason is that the parser will try to validate your code, even the code that won't be executed because its IF condition wouldn't be met.
The parser is smart enough to see there is no table named name, but it's not smart enough to realize that the code shouldn't get executed because of the IF, so it raises a parsing error.
Using dynamic SQL in the BEGIN..END block after the IF hides this from the parser so it will execute.
Try this:
IF EXISTS(SELECT *
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'myTableName'
AND COLUMN_NAME = 'ColumnA')
BEGIN
// your update and drop code goes here
END
you might want to check your account privileges if you are modifying table structure etc..
I have the following SQL in SQL Server 2005 but I get an error stating "Invalid column name 'ExpIsLocalTime' (ln 7) when I run it:
IF NOT EXISTS(SELECT * FROM sys.columns WHERE Name = N'ExpIsLocalTime' AND Object_ID = Object_ID(N'[dbo].[tbl_SessionsAvailable]'))
BEGIN
ALTER TABLE dbo.tbl_SessionsAvailable ADD
ExpIsLocalTime bit NOT NULL CONSTRAINT DF_tbl_SessionsAvailable_ExpIsLocalTime DEFAULT (0)
UPDATE dbo.tbl_SessionsAvailable
SET ExpIsLocalTime = 1
END
GO
This will be in a script file that may be run more than once so I'm trying to make sure the UPDATE only runs once. Is there something about BEGIN/END that delays the execution of the DDL statement?
Your SQL query to do the UPDATE refers to a column that has not yet been created. At compile time, SQL Server detects that the column does not exist, so it gives you the error "Invalid column name 'ExpIsLocalTime'".
In order to include the UPDATE in this query, you will need to encapsulate it in a dynamic SQL query. In other words, something like this:
IF NOT EXISTS(SELECT * FROM sys.columns WHERE Name = N'ExpIsLocalTime' AND Object_ID = Object_ID(N'[dbo].[tbl_SessionsAvailable]'))
BEGIN
ALTER TABLE dbo.tbl_SessionsAvailable ADD
ExpIsLocalTime bit NOT NULL CONSTRAINT DF_tbl_SessionsAvailable_ExpIsLocalTime DEFAULT (0)
DECLARE #SQL NVARCHAR(1000)
SELECT #SQL = N'UPDATE dbo.tbl_SessionsAvailable SET ExpIsLocalTime = 1'
EXEC sp_executesql #SQL
END
GO
We have the same issue in our SQL scripts that maintain tables. After a table is created, if we add a column to it later, we have to use dynamic SQL to avoid these compilation errors.
Another possibly simpler solution is using the GO statement after the Alter statement. This would send the DDL to the server. Then run the rest of your SQL. This should work if you are using sqlcmd osql or SSMS.
I executed this SQL statement in Postgres
alter table user modify column 'distinguishedName1' text;
and
alter table user modify column distinguishedName1 text;
user is the table name
distinguishedName1 is the column name with integer data type.
I wanted to modify the data type to boolean or text or varchar(256) etc based on user's input. But when I run the query I get the error
ERROR: syntax error at or near "modify"
Not sure what is the problem. Help required on right query.
POSTGRES syntax for altering column type :
ALTER TABLE user ALTER COLUMN distinguishedName1 TYPE text;
Try this:
ALTER TABLE "user" ALTER COLUMN distinguishedName1 TYPE text USING code::text;
or
ALTER TABLE "user" ALTER COLUMN distinguishedName1 TYPE text
Also do note that the USING is optional. See the manual here:
The optional USING clause specifies how to compute the new column
value from the old; if omitted, the default conversion is the same as
an assignment cast from old data type to new. A USING clause must be
provided if there is no implicit or assignment cast from old to new
type.
On a side note try to avoid naming your tables as reserved keywords.
alter table user Alter column distinguishedName1 text;
Syntax mistake , for sql server you have to use alter to modify the column of table
I want to add a nullable boolean column to an existing table with default value of null.
I have used this bit of script but it does not set the default value to null. it sets it to 0 instead.
ADD newColumnName BIT NULL
CONSTRAINT DF_tableName_newColumnName DEFAULT(null)
I just ran your example code snippet on my SQL Server 2008 R2 instance and then inserted a record. It initialized the column to null, as expected. The next step would be to post the alter statement and the insert statement that you used.
I used:
alter table tmp1 Add newColumnName bit null CONSTRAINT DF_tableName_newColumnName DEFAULT(null)
insert into tmp1(emp_id) values(9999)
select * from tmp1
After running the above, I used SQL Server Management Studio "Design" action to examine the properties of the new column. It showed that the "Default Value or Binding" was indeed (Null) as expected.
I am using Oracle Database (version is 9i) and I want to add a column to a current table in oracle database.
I want to add an integer column to keep track of invalid tries per user, so default value should be 5.
When I try to execute this query in Sql*Plus it gives an error table or view doesn't exist ( I have double checked table name is correct.
ALTER TABLE CustApps_user ADD VALID_TRIES INT DEFAULT 5 NOT NULL;
I guess the error you're getting is ORA-00942. This can mean a number of things, but basically it means the object does not exist in the current scope and context of what you're doing. So for instance it is the error thrown when we attempt to build a view on a table in another schema when we have been granted privileges through a role and not directly.
In your case it probably mean that the table is in another schema. You normally may be accessing it through a view or synonym. You can easily check this by querying the data dictionary:
select owner, object_type
from all_objects
where object_name = 'CUSTAPPS_USER'
alter table
table_name
add
(
column1_name column1_datatype column1_constraint,
column2_name column2_datatype column2_constraint,
column3_name column3_datatype column3_constraint
);
Here are some examples of Oracle "alter table" syntax to add data columns.
alter table
cust_table
add
cust_sex varchar2(1) NOT NULL;
Here is an example of Oracle "alter table" syntax to add multiple data columns.
ALTER TABLE
cust_table
ADD
(
cust_sex char(1) NOT NULL,
cust_credit_rating number
);
You have to add bracket in query:
ALTER TABLE CustApps_user ADD (VALID_TRIES INT DEFAULT 5 NOT NULL);
INT is legal, but it will be converted to NUMBER, so you can also use:
ALTER TABLE CustApps_user ADD (VALID_TRIES NUMBER(38,0) DEFAULT 5 NOT NULL);
or change (decrease) NUMBER precision.