Anonymous Blocks
An anonymous block is one of the character blocks of a stored procedure and has no name. It is generally used for scripts or activities that are not executed frequently.
Syntax
Figure 1 shows the syntax diagram for an anonymous block.
Details about the syntax diagram are as follows:
The execution section of an anonymous block starts with a BEGIN statement, has a break with an END statement, and ends with a semicolon (;). Type a slash (/) and press Enter to execute the statement.
NOTICE:
The terminator “/” must be written in an independent row.The declaration section includes the variable definition, type, and cursor definition.
A simplest anonymous block does not execute any commands. At least one statement, even a NULL statement, must be presented in any implementation blocks.
Parameter Description
DECLARE
Specifies an optional keyword used to begin a DECLARE statement. This keyword can be used to declare a data type, variable, or cursor. The use of this keyword depends on the context in which the block is located.
declaration_statements
Specifies the declaration of a data type, variable, cursor, exception, or procedure whose scope is limited to the block. Each declaration must be terminated with a semicolon (;).
BEGIN
Specifies the mandatory keyword for introducing an executable section. The section can contain one or more SQL or PL/SQL statements. A BEGIN-END block can contain nested BEGIN-END blocks.
execution_statements
Specifies PL/SQL or SQL statements. Each statement must be terminated with a semicolon (;).
END
Specifies the required keyword for ending a block.
Examples
-- Create a null statement block.
openGauss=# BEGIN
NULL;
END;
/
-- Create a demonstration table.
openGauss=# CREATE TABLE table1(id1 INT, id2 INT, id3 INT);
CREATE TABLE
-- Use an anonymous block to insert data.
openGauss=# BEGIN
insert into table1 values(1,2,3);
END;
/
ANONYMOUS BLOCK EXECUTE
-- Query the inserted data.
openGauss=# select * from table1;
id1 | id2 | id3
-----+-----+-----
1 | 2 | 3
(1 rows)