Modifying columns in a table

What?
This is an article to remind me how to modify a column in a database table the old fashioned way (as in stop making me use GUI interfaces so poorly programmed when even I've made better DBMS tools).

All SQL
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-- Add a column to an existing table (giving it datatype char(2) and allowing NULL)
ALTER TABLE myTable ADD myColumn CHAR(2) NULL

-- Delete a column
ALTER TABLE myTable DROP COLUMN myColumn 

-- Reorder a column
ALTER TABLE myTable MODIFY COLUMN misplacedColumn AFTER otherColumn;
  1.  -- Add a column to an existing table (giving it datatype char(2) and allowing null) 
  2.  ALTER TABLE myTable ADD myColumn CHAR(2) NULL 
  3.   
  4.  -- Delete a column 
  5.  ALTER TABLE myTable DROP COLUMN myColumn 
  6.   
  7.  -- Reorder a column 
  8.  ALTER TABLE myTable MODIFY COLUMN misplacedColumn AFTER otherColumn; 

MySQL and Oracle PL/SQL
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ALTER TABLE myTable
MODIFY myColumn myDataType
  1.  ALTER TABLE myTable 
  2.  MODIFY myColumn myDataType 

Microsoft Transact SQL (T-SQL)
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ALTER TABLE myTable
ALTER COLUMN myColumn myDataType
  1.  ALTER TABLE myTable 
  2.  ALTER COLUMN myColumn myDataType 

Category: Databases :: Article: 514

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