I am trying to change a column from a varchar(50)
to a nvarchar(200)
. What is the SQL command to alter this table?
This question is related to
sql-server
tsql
type-conversion
alter-table
Don't forget nullability.
ALTER TABLE <schemaName>.<tableName>
ALTER COLUMN <columnName> nvarchar(200) [NULL|NOT NULL]
As long as you're increasing the size of your varchar you're OK. As per the Alter Table reference:
Reducing the precision or scale of a column may cause data truncation.
The syntax to modify a column in an existing table in SQL Server (Transact-SQL) is:
ALTER TABLE table_name
ALTER COLUMN column_name column_type;
For example:
ALTER TABLE employees
ALTER COLUMN last_name VARCHAR(75) NOT NULL;
This SQL Server ALTER TABLE
example will modify the column called last_name
to be a data type of VARCHAR(75)
and force the column to not allow null values.
see here
Use the Alter table statement.
Alter table TableName Alter Column ColumnName nvarchar(100)
ALTER TABLE [dbo].[TableName]
ALTER COLUMN ColumnName VARCHAR(Max) NULL
For changing data type
alter table table_name
alter column column_name datatype [NULL|NOT NULL]
For changing Primary key
ALTER TABLE table_name
ADD CONSTRAINT PK_MyTable PRIMARY KEY (column_name)
Try this:
ALTER TABLE "table_name"
MODIFY "column_name" "New Data Type";
Source: Stackoverflow.com