Add check constraint

sql

ALTER TABLE products
ADD CONSTRAINT chk_price_positive CHECK (price >= 0);

Explanation

CHECK constraints enforce domain rules inside the database.

Learn the surrounding workflow

Compare similar commands or jump into common fixes when this command is part of a bigger troubleshooting path.

Same sheet · prioritizing Constraints and Indexes

Mark a column as the main row identifier.

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Ensure a column or column set stays unique.

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Add an index to improve lookup performance.

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Index multiple columns together.

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Attach a foreign key or check constraint after table creation.

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Define a new table with columns and constraints.