Can my DB?

CREATE TABLE products (
  id INT PRIMARY KEY,
  price NUMERIC NOT NULL,
  CONSTRAINT price_positive CHECK (price > 0)
);

• NOT VALID adds the constraint without scanning existing rows; VALIDATE CONSTRAINT validates them later without a long exclusive lock on INSERT/UPDATE.

CREATE TABLE products (
  id INT PRIMARY KEY,
  price DECIMAL(10,2) NOT NULL,
  CONSTRAINT price_positive CHECK (price > 0)
);

• Enforced since 8.0.16; parsed and ignored before that.
• Cannot reference user-defined or stored functions.

CREATE TABLE products (price DECIMAL(10,2) CHECK (price > 0));

• Enforced since 10.2.1; parsed and ignored before that.

CREATE TABLE products (
  id NUMBER PRIMARY KEY,
  price NUMBER NOT NULL,
  CONSTRAINT price_positive CHECK (price > 0)
);

• SYSDATE and other deterministic functions are allowed; subqueries, other rows, and other tables are not.

CREATE TABLE products (
  id INT PRIMARY KEY,
  price DECIMAL(10,2) NOT NULL,
  CONSTRAINT price_positive CHECK (price > 0)
);

• ALTER TABLE ... WITH NOCHECK ADD CONSTRAINT adds the constraint without validating existing rows; trigger or FK-based workarounds handle cross-table checks.

CREATE TABLE products (
  id INTEGER PRIMARY KEY,
  price REAL NOT NULL CHECK (price > 0)
);

CREATE TABLE products (
  id INT PRIMARY KEY,
  price DECIMAL(10,2) NOT NULL,
  CONSTRAINT price_positive CHECK (price > 0)
);

• Accepted and stored in pg_constraint but not evaluated during INSERT, UPDATE, or COPY. Documentation only.

CREATE TABLE products (
  id INT PRIMARY KEY,
  price DECIMAL(10,2) NOT NULL,
  CONSTRAINT price_positive CHECK (price > 0)
);

• Violations raise SQLSTATE 23513.
• SET INTEGRITY FOR t OFF suspends checking for bulk loads; re-enable with SET INTEGRITY ... IMMEDIATE CHECKED.

CREATE TABLE products (
  id INT PRIMARY KEY,
  price DECIMAL(10,2) NOT NULL,
  CONSTRAINT price_positive CHECK (price > 0)
);

• Accepted but not evaluated on DML. Only NOT NULL is actually enforced on standard tables.

• Not supported. Enforce at the application layer or in an ELT step.