Alter table

Alter table

1. Agregar columna

   • ALTER TABLE Customers ADD Email varchar(255);

2. Eliminar columna

   • ALTER TABLE Customers DROP COLUMN Email;

3. Modificar columna

   • ALTER TABLE table_name ALTER COLUMN column_name datatype;

4. Modificar columna

   • ALTER TABLE table_name MODIFY COLUMN column_name datatype;

5. Cambiar tipo de dato

   • ALTER TABLE Persons ALTER COLUMN DateOfBirth year;

6. Agregar columnas

   • ALTER TABLE supplier ADD (supplier_name char(50), city char(45));

7. Modificar columnas

   • ALTER TABLE supplier MODIFY supplier_name VARCHAR(100) NOT NULL, MODIFY city VARCHAR(75);

8. Renombrar columna

   • ALTER TABLE supplier CHANGE COLUMN supplier_name sname VARCHAR(100);

9. Renombrar tabla

   • ALTER TABLE table_name RENAME TO new_table_name;

10. Agregar numero autoincrementable

    • ALTER TABLE t2 ADD c INT UNSIGNED NOT NULL AUTO_INCREMENT, ADD PRIMARY KEY (c);

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