Executing Dynamic Non-query Statements

Syntax

Figure 1 shows the syntax diagram.

Figure 1 noselect::=

Figure 2 shows the syntax diagram for using_clause.

Figure 2 using_clause::=

The above syntax diagram is explained as follows:

USING IN bind_argument is used to specify the variable whose value is passed to the dynamic SQL statement. The variable is used when a placeholder exists in dynamic_noselect_string. That is, a placeholder is replaced by the corresponding bind_argument when a dynamic SQL statement is executed. Note that bind_argument can only be a value, variable, or expression, and cannot be a database object such as a table name, column name, and data type. If a stored procedure needs to transfer database objects through bind_argument to construct dynamic SQL statements (generally, DDL statements), you are advised to use double vertical bars (||) to concatenate dynamic_select_clause with a database object. In addition, a dynamic PL/SQL block allows duplicate placeholders. That is, a placeholder can correspond to only one bind_argument.

Examples

    
     
       
       
         -- Create a table.
openGauss=# CREATE TABLE sections_t1
(
   section       NUMBER(4) ,
   section_name  VARCHAR2(30),
   manager_id    NUMBER(6),
   place_id      NUMBER(4) 
);

-- Declare a variable.
openGauss=# DECLARE 
   section       NUMBER(4) := 280; 
   section_name  VARCHAR2(30) := 'Info support'; 
   manager_id    NUMBER(6) := 103;
   place_id      NUMBER(4) := 1400;
   new_colname   VARCHAR2(10) := 'sec_name';
BEGIN 
-- Execute the query.
    EXECUTE IMMEDIATE 'insert into sections_t1 values(:1, :2, :3, :4)' 
       USING section, section_name, manager_id,place_id; 
-- Execute the query (duplicate placeholders).
    EXECUTE IMMEDIATE 'insert into sections_t1 values(:1, :2, :3, :1)' 
       USING section, section_name, manager_id; 
-- Run the ALTER statement. (You are advised to use double vertical bars (||) to concatenate the dynamic DDL statement with a database object.)
    EXECUTE IMMEDIATE 'alter table sections_t1 rename section_name to ' || new_colname;
END; 
/

-- Query data.
openGauss=# SELECT * FROM sections_t1;

-- Delete the table.
openGauss=# DROP TABLE sections_t1;

        

      

    
   