DO — execute an anonymous code block
DO [ (type[, ...]) USING (argument[, ...]) ] [ LANGUAGElang_name]code
DO executes an anonymous code block, or in other
words a transient anonymous function in a procedural language.
The code block is treated as though it were the body of a function
with no parameters, returning void. It is parsed and
executed a single time.
With the USING clause, the code block is treated as though it were the body of a function
with parameters, returning record.
With prepareStatement, it can be parsed once and executed multiple times, but it is cheap to parse it.
Normally it used in ecpg.
The optional USING clause can be written either
before or after the code block, but it can only be used for pl/sql now.
The optional LANGUAGE clause can be written either
before or after the code block.
code
The procedural language code to be executed. This must be specified
as a string literal, just as in CREATE FUNCTION.
Use of a dollar-quoted literal is recommended.
lang_name
The name of the procedural language the code is written in.
If omitted, the default is plpgsql.
typeThe type of the argument. the argument's mode is always inout.
argumentThe argument used for executing an anonymous code block like CALL.
The procedural language to be used must already have been installed
into the current database by means of CREATE EXTENSION.
plpgsql is installed by default, but other languages are not.
The user must have USAGE privilege for the procedural
language, or must be a superuser if the language is untrusted.
This is the same privilege requirement as for creating a function
in the language.
If DO is executed in a transaction block, then the
procedure code cannot execute transaction control statements. Transaction
control statements are only allowed if DO is executed in
its own transaction.
Grant all privileges on all views in schema public to
role webuser:
DO $$DECLARE r record;
BEGIN
FOR r IN SELECT table_schema, table_name FROM information_schema.tables
WHERE table_type = 'VIEW' AND table_schema = 'public'
LOOP
EXECUTE 'GRANT ALL ON ' || quote_ident(r.table_schema) || '.' || quote_ident(r.table_name) || ' TO webuser';
END LOOP;
END$$;
Grant all privileges on all views in schema public to
role webuser by arguments in LANGUAGE pl/sql:
DO $$DECLARE r record;
BEGIN
FOR r IN SELECT table_schema, table_name FROM information_schema.tables
WHERE table_type = $1 AND table_schema = $2
LOOP
EXECUTE 'GRANT ALL ON ' || quote_ident(r.table_schema) || '.' || quote_ident(r.table_name) || ' TO webuser';
END LOOP;
END$$ (text, text) USING ('VIEW', 'public') LANGUAGE plorasql;
See Section 33.5.4 for the usage in ecpg(Oracle Pro*c compatible).
There is no DO statement in the SQL standard.