STATEMENT: CREATE TABLE
CREATE TABLE table (field1 type [(size)] [NOT NULL] [index1]
[, field2 type [(size)] [NOT NULL] [index2] [, ...]]
[, CONSTRAINT multifieldindex [, ...]])
The CREATE TABLE statement is used to create
a new table and its fields. At its simplest you can create a table
containing only a single field by specifying the name you want to
give the table, the field name
and the type of data you want the field to contain:
CREATE TABLE Names (Name TEXT);
You can, of course, include more than one field, and also
limit the size of those fields (Text and Binary fields only)
by stating the size in parentheses after the data type declaration:
CREATE TABLE Names (FirstName TEXT (20), LastName TEXT (20) );
If you require that a particular field must always
have valid data entered into it, you can include the expression
NOT NULL at the end of the declaration for that field.
If you do not enter the required data, you will get a warning
message:
CREATE TABLE Names (FirstName TEXT (20), LastName TEXT (20)
NOT NULL);
More often than not, you'll want to place
some sort of restriction on the data, or combinations of data, that
are entered into fields. You can do this
by using the CONSTRAINT clause.
The following example expands on the
previous ones by adding a Date of Birth field and requiring
that the combination of data in all three fields be unique:
CREATE TABLE Names (FirstName TEXT (20),
LastName TEXT (20), DateOfBirth DATETIME,
CONSTRAINT MultiConstraint
UNIQUE(FirstName, LastName, DateOfBirth) );
Microsoft warns, "The Microsoft Jet database engine doesn't support the use of any DDL
statements with databases produced by any other database engine.
Use the DAO (Data Access Objects) Create methods instead."
Copyright 2000 by Infinite Software Solutions, Inc.
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