Create (SQL)

A CREATE statement in SQL creates an object inside of a relational database management system (RDBMS). The types of objects that can be created depends on which RDBMS is being used, but most support the creation TABLEs, INDEXes, USERs, and DATABASEs. Some systems (such as PostgreSQL) allow CREATE and other DDL comands to occur inside of a transaction and thus be rolled back.

CREATE TABLE

Perhaps the most common CREATE command is the CREATE TABLE command. The typical usage is:

CREATE TABLE [table_name] ( [column_name type (size)] [column_name type (size)]) .

Column Defitions: A comma-separated list consisting of any of the following

Column definition: [column name] [data type] {NULL | NOT NULL} {column options}
Primary key definition: PRIMARY KEY ( [comma separated column list] )
CONTRAINTS: {CONSTRAINT}} [constraint definition]
RDBMS specific functionality

For example, the command to create a table named employees with a few sample columns would be:

CREATE TABLE employees 
  (empno         INTEGER   not null
  ,empfname      CHAR(50)  null
  ,emplname      CHAR(75)  not null
  ,date_of_birth DATE      null
  ,PRIMARY KEY (empno)
 );

For example, the command to create a table named teachers with a few sample columns would be:

CREATE TABLE teachers 
  (tno            CHAR (4)     not null
  ,tname          CHAR(45)     null
  ,taddress       CHAR(65)     not null
  ,salary         NUMBER (7,2) null
  ,date_of_joinig DATE         not null
  ,date_of_birth  DATE         null
  ,dept_no        CHAR (4)     null
  ,PRIMARY KEY (tno)
 );