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ahmetonurslmz/sql_on_delete.md

Created August 22, 2020 12:56
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SQL - Attitudes types to adopted record when referenced record is deleted
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sql_on_delete.md

  1. CASCADE: This enables us to remove its all adopted records when parent is deleted. For example, we have removed blog record, its adopted comment records will be deleted.

  2. RESTRICT: This enables us to prevent deletion of record when it has a adopted record at least.

  3. These enable us to set data that we want into relation column of adopted records that we will remove its parent.

  • SET NULL:
  • SET DEFAULT:
  • SET (...):
  1. NO ACTION: It does not anything. You should avoid choose this inside all of these choices.
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