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Learn/SQL/SQL References

SQL•SQL References

SQL ALTER TABLE Keyword

Concept visual

SQL ALTER TABLE Keyword

Pointer walk

two pointers

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right=6

1

3

Start at both ends

ALTER TABLE Keyword

Alter Table

The ALTER TABLE

command adds, deletes, or modifies columns in a table.

The ALTER TABLE

command also adds and deletes various constraints in a table. The following SQL adds an "Email" column to the "Customers" table:

Example

ALTER TABLE Customers

ADD Email varchar(255);
The following SQL deletes the "Email" column from the "Customers" table:

Example

ALTER TABLE Customers

DROP COLUMN Email;

SQL ALTER TABLE Keyword

Concept visual

SQL ALTER TABLE Keyword

Pointer walk

two pointers

left=0

right=6

1

3

Start at both ends

ALTER TABLE Keyword

Alter Table

The ALTER TABLE

command adds, deletes, or modifies columns in a table.

The ALTER TABLE

command also adds and deletes various constraints in a table. The following SQL adds an "Email" column to the "Customers" table:

Example

ALTER TABLE Customers

ADD Email varchar(255);
The following SQL deletes the "Email" column from the "Customers" table:

Example

ALTER TABLE Customers

DROP COLUMN Email;

SQL ALTER TABLE Keyword

SQL ALTER TABLE Keyword

ALTER TABLE Keyword

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Alter Table

The ALTER TABLE

The ALTER TABLE

Example

ALTER TABLE Customers

Example

ALTER TABLE Customers

Previous

Next

SQL ALTER TABLE Keyword

SQL ALTER TABLE Keyword

ALTER TABLE Keyword

Previous

Next

Alter Table

The ALTER TABLE

The ALTER TABLE

Example

ALTER TABLE Customers

Example

ALTER TABLE Customers

Previous

Next