SQL Constraints: Difference between revisions
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| Line 3: | Line 3: | ||
=Overview= | =Overview= | ||
=<tt>NOT NULL</tt> Constraint= | |||
=Primary Key Constraint= | =Primary Key Constraint= | ||
Revision as of 00:00, 23 May 2024
Internal
Overview
NOT NULL Constraint
Primary Key Constraint
CREATE TABLE ...
( ...
CONSTRAINT pk_someconstraint PRIMARY KEY (somecolumn)
);
Check Constraint
CREATE TABLE ...
( ...
eye_color CHAR(2) CHECK (eye_color IN ('BR', 'BL', 'GR')),
...
);