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Overview

The pg_get_constraintdef() is a system catalog information function that retrieves the definition of a specific constraint in a human-readable format.

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Syntax

The syntax for the pg_get_constraintdef() function is as follows: 
pg_get_constraintdef (constraint_oid [, pretty_bool]) → NULL

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Parameters

The following parameters are required to execute this function:
  • constraint_oid: specifies the object identifier (OID) of the constraint for which you want to retrieve the definition
  • pretty_bool: controls whether to format the output in a human-readable way

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Restrictions

  • This function always returns NULL if there are no parameters specified