Tutorials References Menu

SQL Tutorial

SQL HOME SQL Intro SQL Syntax SQL Select SQL Select Distinct SQL Where SQL And, Or, Not SQL Order By SQL Insert Into SQL Null Values SQL Update SQL Delete SQL Select Top SQL Min and Max SQL Count, Avg, Sum SQL Like SQL Wildcards SQL In SQL Between SQL Aliases SQL Joins SQL Inner Join SQL Left Join SQL Right Join SQL Full Join SQL Self Join SQL Union SQL Group By SQL Having SQL Exists SQL Any, All SQL Select Into SQL Insert Into Select SQL Case SQL Null Functions SQL Stored Procedures SQL Comments SQL Operators

SQL Database

SQL Create DB SQL Drop DB SQL Backup DB SQL Create Table SQL Drop Table SQL Alter Table SQL Constraints SQL Not Null SQL Unique SQL Primary Key SQL Foreign Key SQL Check SQL Default SQL Index SQL Auto Increment SQL Dates SQL Views SQL Injection SQL Hosting SQL Data Types

SQL References

SQL Keywords MySQL Functions SQL Server Functions MS Access Functions SQL Quick Ref

SQL Examples

SQL Examples

SQL TABLE Keyword

❮ SQL Keywords Reference


CREATE TABLE

The CREATE TABLE command creates a new table in the database.

The following SQL creates a table called "Persons" that contains five columns: PersonID, LastName, FirstName, Address, and City:

Example

CREATE TABLE Persons (
    PersonID int,
    LastName varchar(255),
    FirstName varchar(255),
    Address varchar(255),
    City varchar(255)
);
Try it Yourself »

CREATE TABLE Using Another Table

A copy of an existing table can also be created using CREATE TABLE.

The following SQL creates a new table called "TestTables" (which is a copy of the "Customers" table): 

Example

CREATE TABLE TestTable AS
SELECT customername, contactname
FROM customers;
Try it Yourself »

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);
Try it Yourself »

The following SQL deletes the "Email" column from the "Customers" table:

Example

ALTER TABLE Customers
DROP COLUMN Email;
Try it Yourself »

DROP TABLE

The DROP TABLE command deletes a table in the database.

The following SQL deletes the table "Shippers":

Example

DROP TABLE Shippers;
Try it Yourself »

Note: Be careful before deleting a table. Deleting a table results in loss of all information stored in the table!


TRUNCATE TABLE

The TRUNCATE TABLE command deletes the data inside a table, but not the table itself.

The following SQL truncates the table "Categories": 

Example

TRUNCATE TABLE Categories;
Try it Yourself »

❮ SQL Keywords Reference