create table
Define a new table
Syntax
create_table: CREATE TABLE table_name (column_def [, column_def]... [, tab_constraint]...)
Description
The CREATE TABLE statement is used to define a table that will be used in creating a database. The CREATE TABLE statement may also include additional information that defines relationships between tables in the same schema definition. A schema may have multiple tables defined. The table_name is a user-specified identifier that names the table. Within the current schema definition, table names cannot be duplicated.
The optional constraint clauses specify constraints (tests) that new or updated rows must satisfy for an insert or update operation to succeed. A constraint is an SQL object that helps define the set of valid values in the table in various ways.
There are two ways to define constraints: table constraints and column constraints. A column constraint is defined as part of a column definition. A table constraint definition is not tied to a particular column, and it can encompass more than one column. Every column constraint can also be written as a table constraint; a column constraint is only a notational convenience for use when the constraint only affects one column.
Components
table_name | The name of the table to be created. |
column_def | The name and data type of a column to be created in the new table. For more information on the structure of the column definition components, refer to the Column Definitions section. |
tab_constraint | Optional table constraints that can be declared (keys or foreign keys). For more information on table constraints, refer to the Table Constraint Declarations section. |
Example
CREATE TYPE money AS decimal(10,2); CREATE TABLE acctmgr( mgrid CHAR(7 OCTETS) PRIMARY KEY, name CHAR(24), hire_date DATE, commission DECIMAL(4,3) ); CREATE TABLE patron( patid CHAR(3 OCTETS) PRIMARY KEY, name CHAR(30), street CHAR(35), city CHAR(17), state CHAR(2 OCTETS), country CHAR(2 OCTETS), pc CHAR(10), email CHAR(63 OCTETS), phone CHAR(15 OCTETS), mgrid CHAR(7 OCTETS) REFERENCES acctmgr ON UPDATE CASCADE, notes LONG VARCHAR ); CREATE TABLE author( last_name CHAR(13) PRIMARY KEY, full_name CHAR(35), gender CHAR(1 OCTETS), yr_born SMALLINT, yr_died SMALLINT, short_bio VARCHAR(216), CONSTRAINT yob_gender_key KEY (yr_born, gender) ); CREATE TABLE genres( text CHAR(31) PRIMARY KEY ); CREATE TABLE subjects( text CHAR(51) PRIMARY KEY ); CREATE TABLE book( bookid CHAR(14 OCTETS) PRIMARY KEY, last_name CHAR(13) REFERENCES author ON DELETE CASCADE ON UPDATE CASCADE, title VARCHAR(105) KEY, descr CHAR(61), publisher VARCHAR(136), publ_year SMALLINT KEY, lc_class CHAR(33), date_acqd DATE, date_sold DATE, price MONEY, cost MONEY, notes LONG VARCHAR ); CREATE TABLE related_name( bookid CHAR(14 OCTETS) REFERENCES book ON DELETE CASCADE ON UPDATE CASCADE, name CHAR(61) ); CREATE TABLE genres_books( bookid CHAR(14 OCTETS) REFERENCES book ON DELETE CASCADE ON UPDATE CASCADE, genre CHAR(31) REFERENCES genres ); CREATE TABLE subjects_books( bookid CHAR(14 OCTETS) REFERENCES book ON DELETE CASCADE ON UPDATE CASCADE, subject CHAR(51) REFERENCES subjects ); CREATE TABLE sale( bookid CHAR(14 OCTETS) REFERENCES book ON DELETE CASCADE ON UPDATE CASCADE, patid CHAR(3 OCTETS) REFERENCES patron ON DELETE CASCADE ON UPDATE CASCADE ); CREATE TABLE auction( aucid INTEGER PRIMARY KEY, bookid CHAR(14 OCTETS) REFERENCES book ON DELETE CASCADE ON UPDATE CASCADE, mgrid CHAR(7 OCTETS) REFERENCES acctmgr ON UPDATE CASCADE, start_date DATE, end_date DATE, reserve MONEY, curr_bid MONEY, bid_time TIME ); CREATE TABLE bid( aucid INTEGER REFERENCES auction ON DELETE CASCADE ON UPDATE CASCADE, patid CHAR(3 OCTETS) REFERENCES patron ON DELETE CASCADE ON UPDATE CASCADE, offer MONEY, bid_ts TIMESTAMP );
See Also