DO

Synopsis

Use the DO statement to execute 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.The optional LANGUAGE clause can be written either before or after the code block.

Syntax

  1. do ::= DO [ LANGUAGE lang_name ] code

do

DO - 图1

Semantics

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.The procedural language to be used must already have been installed into the current database. plpgsql is installed by default, but other languages are not.

Notes

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.

Examples

  1. DO $$DECLARE r record;
  2. BEGIN
  3. FOR r IN SELECT table_schema, table_name FROM information_schema.tables
  4. WHERE table_type = 'VIEW' AND table_schema = 'public'
  5. LOOP
  6. EXECUTE 'GRANT ALL ON ' || quote_ident(r.table_schema) || '.' || quote_ident(r.table_name) || ' TO webuser';
  7. END LOOP;
  8. END$$;

See also

Other YSQL Statements