Returns a PostgreSQL function that can be triggered to prevent UPDATEs to a database table.

Examples

iex> create_prevent_update_function()
"CREATE OR REPLACE FUNCTION prevent_update()..."

Returns a PostgreSQL command that drops the function created by create_prevent_update_function/0, if it exists.

Examples

iex> drop_prevent_update_function()
"DROP FUNCTION IF EXISTS prevent_update();"

Returns a PostgreSQL command to create a database trigger that prevents UPDATEs to the given Ecto.Migration.Table.

Examples

iex> protect(table("users"))
"CREATE OR REPLACE TRIGGER prevent_update..."

Returns a PostgreSQL command to create a database trigger that prevents UPDATEs to the given columns of the Ecto.Migration.Table.

Examples

iex> protect(table("users"), [:uuid, :birthdate])
"DO $$..."

iex> protect(table("users"), [:uuid], nullable: true)
"DO $$..."

Options

• nullable - Whether the columns can be set to NULL; defaults to false