I am trying to update the dbo.sysusers table so that the sid matches the dbo.syslogins table but I am getting error:
Disallowed implicit conversion from data type varchar to data type varbinary, table 'CallingCard.dbo.sysusers', column 'sid'. Use the CONVERT function to run this query.
My syntax for the update is:
UPDATE CallingCard.dbo.sysusers
SET sid = '0xDF5B9900C8FCAE438B0F4177B5'
WHERE uid = 6
I don't know how to update a varbinary column. How do i fix this?
Related
One of my column is defined as ntext datatype which is no longer supported by many streams. I'm trying my best to convert that column to numeric or int and every attempt is reaching anywhere.
reg_no #my ntext field | name | country | etc |
I tried to alter the col using the command we all use, but failed
alter table tabl1
alter column [reg_no] numeric(38,0)
Error:
Error converting data type nvarchar to numeric
Any suggestions on fixing this or has anyone come across this in the past, if yes how did you get over it
You should be able to do this in two steps:
alter table tabl1 alter column [reg_no] nvarchar(max);
alter table tabl1 alter column [reg_no] numeric(38,0);
ntext is deprecated and conversion to numeric is not supported, but converting to nvarchar() is supported.
This assumes that the values are compatible with numeric. Otherwise you will get a type conversion error. If this happens, you can get the offending values by using:
select *
from t
where try_convert(numeric(38, 0), try_convert(nvarchar(max), x)) is null
Try,
select convert(int,convcert(varchar(40), reg_no)) as newfieldname from tabl1
I am changing the postgresql column data type from integer[] to integer, while executing below query,
alter table contact_type alter column is_delete set data type integer USING is_delete::integer
i am getting below error
ERROR: cannot cast type integer[] to integer
LINE 1: ...umn is_delete set data type integer USING is_delete::integer
^
SQL state: 42846
Character: 86
but when tried to change datatype from varchar[] to char, below query works fine
alter table contact_type alter column ct_type set data type varchar
i have referred this link so link but it is not working for converting array to normal data type..
Edit :- it is empty table without any data...
You need to pick the array element that you want to use. You can't convert e.g. 42 integers to a single one.
E.g. if you want to use the first element of the array:
alter table contact_type
alter column is_delete
set data type integer USING is_delete[1];
But a column named is_delete should probably be a boolean rather than an integer.
Is it possible to copy data from column A to column B for all records in a table in SQL?
How about this
UPDATE table SET columnB = columnA;
This will update every row.
UPDATE table_name SET
destination_column_name=orig_column_name
WHERE condition_if_necessary
This will update all the rows in that columns if safe mode is not enabled.
UPDATE table SET columnB = columnA;
If safe mode is enabled then you will need to use a where clause.
I use primary key as greater than 0 basically all will be updated
UPDATE table SET columnB = columnA where table.column>0;
If you want to copy a column to another column with a different data type in PostgresSQL, you must cast/convert to the data type first, otherwise it will return
Query 1 ERROR: ERROR: column "test_date" is of type timestamp without
time zone but expression is of type character varying LINE 1: update
table_name set test_date = date_string_col
^ HINT: You will need to rewrite or cast the expression.
An example of converting varchar to timestamp:
update table_name set timestamp_col = date_string_col::TIMESTAMP;
An example of converting varchar to int:
update table_name set int_column = string_col::INTEGER;
but any column type(except file or the similar) can be copied to string(character varying) without cast the type.
This question already has answers here:
Rails Migrations: tried to change the type of column from string to integer
(6 answers)
Closed 8 years ago.
I am using the following query to change the data type of a column from text to integer but getting error:
alter table a.attend alter column terminal TYPE INTEGER ;
ERROR: column "terminal" cannot be cast automatically to type integer
create table test(id varchar );
insert into test values('1');
insert into test values('11');
insert into test values('12');
select * from test
--Result--
id
character varying
--------------------------
1
11
12
You can see from the above table that I have used the data type – character varying for id
column. But it was a mistake because I am always giving integers as id. So using varchar here is a bad practice. So let’s try to change the column type to integer.
ALTER TABLE test ALTER COLUMN id TYPE integer;
But it returns:
ERROR: column “id” cannot be cast automatically to type integer SQL
state: 42804 Hint: Specify a USING expression to perform the
conversion
That means we can’t simply change the data type because data is already there in the column. Since the data is of type character varying Postgres can't expect it as integer though we entered integers only. So now, as Postgres suggested we can use the USING expression to cast our data into integers.
ALTER TABLE test ALTER COLUMN id TYPE integer USING (id::integer);
It Works.
So you should use
alter table a.attend alter column terminal TYPE INTEGER USING (terminal::integer) ;
I am using Apache derby database v 10.9.1.0. There is one existing table Country-having column LawID of type bigint. It contains records having integer data only. Due to some business reason, I need to alter its data type from 'bigint' to 'varchar' . I tried following two ways to alter existing table. But both ways did not work.
a. first way
ALTER TABLE Country ADD COLUMN LawID_NEW VARCHAR(50);
UPDATE Country SET LawID_NEW = LawID;
ALTER TABLE Country DROP COLUMN LawID;
RENAME COLUMN Country.LawID_NEW TO LawID;
It shows message like :Columns of type 'VARCHAR' cannot hold values of type 'BIGINT'.
b. second way
ALTER TABLE Country ALTER LawID SET DATA TYPE VARCHAR(50);
It shows error message like : Invalid type specified for column 'LawID'. The type of a column may not be changed.
Any help related to correct alter query is highly appreciated, Thanks
I think the first method would work with this change:
UPDATE Country SET LawID_NEW = TRIM(CHAR(LawID));
ALTER TABLE tablename MODIFY columnname VARCHAR(20);
This works in mysql. Give it a try.
Or
ALTER TABLE table CHANGE columnname columnname VARCHAR(20);