Class: PgSqlTriggers::Testing::DryRun

Inherits:
Object
  • Object
show all
Defined in:
lib/pg_sql_triggers/testing/dry_run.rb

Instance Method Summary collapse

Constructor Details

#initialize(trigger_registry) ⇒ DryRun

Returns a new instance of DryRun.



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# File 'lib/pg_sql_triggers/testing/dry_run.rb', line 6

def initialize(trigger_registry)
  @trigger = trigger_registry
end

Instance Method Details

#estimate_impact ⇒ Object

Show what tables/functions would be affected



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# File 'lib/pg_sql_triggers/testing/dry_run.rb', line 51

def estimate_impact
  definition = JSON.parse(@trigger.definition)
  {
    tables_affected: [@trigger.table_name],
    functions_created: [definition["function_name"]],
    triggers_created: [@trigger.trigger_name]
  }
end

#explain ⇒ Object

Explain the execution plan (does not execute trigger)



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# File 'lib/pg_sql_triggers/testing/dry_run.rb', line 61

def explain
  sql = generate_sql[:sql_parts].pluck(:sql).join("\n\n")

  {
    success: true,
    sql: sql,
    note: "This is a preview only. No changes will be made to the database."
  }
end

#generate_sql ⇒ Object

Generate SQL that WOULD be executed (but don’t execute)



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# File 'lib/pg_sql_triggers/testing/dry_run.rb', line 11

def generate_sql
  definition = JSON.parse(@trigger.definition)
  events = definition["events"].map(&:upcase).join(" OR ")

  sql_parts = []

  # 1. Function creation SQL
  if @trigger.function_body.present?
    sql_parts << {
      type: "CREATE FUNCTION",
      sql: @trigger.function_body,
      description: "Creates the trigger function '#{definition['function_name']}'"
    }
  end

  # 2. Trigger creation SQL
  trigger_timing = "BEFORE" # Could be configurable
  trigger_level = "ROW"     # Could be configurable

  trigger_sql = "CREATE TRIGGER #{@trigger.trigger_name} " \
                "#{trigger_timing} #{events} ON #{@trigger.table_name} " \
                "FOR EACH #{trigger_level}"

  trigger_sql += " WHEN (#{@trigger.condition})" if @trigger.condition.present?
  trigger_sql += " EXECUTE FUNCTION #{definition['function_name']}();"

  sql_parts << {
    type: "CREATE TRIGGER",
    sql: trigger_sql,
    description: "Creates the trigger '#{@trigger.trigger_name}' on table '#{@trigger.table_name}'"
  }

  {
    success: true,
    sql_parts: sql_parts,
    estimated_impact: estimate_impact
  }
end