SQL Constraints: Difference between revisions

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(Created page with "=Internal= * SQL =Overview= =Primary Key Constraint= <syntaxhighlight lang='sql'> CREATE TABLE ... ( ... CONSTRAINT pk_someconstraint PRIMARY KEY (somecolumn) ); </syntaxhighlight>")
 
Line 11: Line 11:
( ...
( ...
   CONSTRAINT pk_someconstraint PRIMARY KEY (somecolumn)
   CONSTRAINT pk_someconstraint PRIMARY KEY (somecolumn)
);
</syntaxhighlight>
=Check Constraint=
<syntaxhighlight lang='sql'>
CREATE TABLE ...
( ...
  eye_color CHAR(2) CHECK (eye_color IN ('BR', 'BL', 'GR')),
  ...
);
);
</syntaxhighlight>
</syntaxhighlight>

Revision as of 23:53, 22 May 2024

Internal

Overview

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')),
  ...
);