22_add_check_constraint.json

{
  "name": "22_add_check_constraint",
  "operations": [
    {
      "alter_column": {
        "table": "posts",
        "column": "title",
        "check": {
          "name": "title_length",
          "constraint": "length(title) > 3"
        },
        "up": "(SELECT CASE WHEN length(title) <= 3 THEN LPAD(title, 4, '-') ELSE title END)",
        "down": "title"
      }
    }
  ]
}