sql remove default value code example

Example 1: sql drop default

Removes a default value for a column.
Example (MySQL): Removes the default value from the ‘name’ column in
the ‘products’ table.
ALTER TABLE products
ALTER COLUMN name DROP DEFAULT;

Example 2: sql script to remove default from column

DECLARE @tableName VARCHAR(MAX) = '<MYTABLENAME>'
DECLARE @columnName VARCHAR(MAX) = '<MYCOLUMNAME>'
DECLARE @ConstraintName nvarchar(200)
SELECT @ConstraintName = Name 
FROM SYS.DEFAULT_CONSTRAINTS
WHERE PARENT_OBJECT_ID = OBJECT_ID(@tableName) 
AND PARENT_COLUMN_ID = (
    SELECT column_id FROM sys.columns
    WHERE NAME = @columnName AND object_id = OBJECT_ID(@tableName))
IF @ConstraintName IS NOT NULL
    EXEC('ALTER TABLE '+@tableName+' DROP CONSTRAINT ' + @ConstraintName)
    
-- Just replace <MYTABLENAME> and <MYCOLUMNNAME>