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Learn/SQL/SQL References

SQL•SQL References

SQL COLUMN Keyword

Concept visual

SQL COLUMN Keyword

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COLUMN Keyword

Alter Column

The ALTER COLUMN

command is used to change the data type of a column in a table. The following SQL changes the data type of the column named "BirthDate" in the "Employees" table to type year:

Example

ALTER TABLE Employees

ALTER COLUMN BirthDate year;

Drop Column

The DROP COLUMN

command is used to delete a column in an existing table. The following SQL deletes the "ContactName" column from the "Customers" table:

Example

ALTER TABLE Customers

DROP COLUMN ContactName;

SQL COLUMN Keyword

Concept visual

SQL COLUMN Keyword

Pointer walk

two pointers

left=0

right=6

1

3

Start at both ends

COLUMN Keyword

Alter Column

The ALTER COLUMN

command is used to change the data type of a column in a table. The following SQL changes the data type of the column named "BirthDate" in the "Employees" table to type year:

Example

ALTER TABLE Employees

ALTER COLUMN BirthDate year;

Drop Column

The DROP COLUMN

command is used to delete a column in an existing table. The following SQL deletes the "ContactName" column from the "Customers" table:

Example

ALTER TABLE Customers

DROP COLUMN ContactName;

SQL COLUMN Keyword

SQL COLUMN Keyword

COLUMN Keyword

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Alter Column

The ALTER COLUMN

Example

ALTER TABLE Employees

Drop Column

The DROP COLUMN

Example

ALTER TABLE Customers

Previous

Next

SQL COLUMN Keyword

SQL COLUMN Keyword

COLUMN Keyword

Previous

Next

Alter Column

The ALTER COLUMN

Example

ALTER TABLE Employees

Drop Column

The DROP COLUMN

Example

ALTER TABLE Customers

Previous

Next