用于在Oracle DBMS中删除记录的存储过程 [英] Stored procedure for deleting records in Oracle DBMS

问题描述

试图弄清楚如何创建一个存储过程，该存储过程将从客户表，customer_order表和line_item表中删除一个客户.这是表格.

Trying to figure out how to create a stored procedure that will delete a customer from the customer table, customer_order table and line_item table. Here are the tables.

CREATE TABLE customer(
    customer_ID DECIMAL(10) NOT NULL,
    customer_first VARCHAR(30),
    customer_last VARCHAR(40),
    customer_total DECIMAL(12, 2),
    PRIMARY KEY (customer_ID));

CREATE TABLE customer_order (
order_id DECIMAL(10) NOT NULL,
customer_id DECIMAL(10) NOT NULL,
order_total DECIMAL(12,2),
order_date DATE,
PRIMARY KEY (ORDER_ID),
FOREIGN KEY (CUSTOMER_ID) REFERENCES customer);

CREATE TABLE line_item(
order_id DECIMAL(10) NOT NULL,
item_id DECIMAL(10) NOT NULL,
item_quantity DECIMAL(10) NOT NULL,
line_price DECIMAL(12,2),
PRIMARY KEY (ORDER_ID, ITEM_ID),
FOREIGN KEY (ORDER_ID) REFERENCES customer_order,
FOREIGN KEY (ITEM_ID) REFERENCES item);

到目前为止，我拥有的SP

Here what I have so far for the SP

CREATE OR REPLACE PROCEDURE DELETE_CUSTOMER(
                                            customer_id_arg    IN DECIMAL,
                                            first_name_arg     IN VARCHAR,
                                            last_name_arg      IN VARCHAR
                                           ) IS
BEGIN
    DELETE FROM CUSTOMER
          WHERE customer_id IN (SELECT customer_last
                                  FROM Customer
                                 WHERE customer_id = customer_id_arg);
END;

当我尝试运行它时，它不会删除记录，而我对于该怎么办感到困惑.

When I try to run it, it doesn't delete a record and I am confused as for what to do.

推荐答案

下面是一个示例代码，用于使用database_dictionary从父级表级联到所有子级表中删除数据，我写它很有趣；-) 请注意从人的最后一行删除，其中pk ='38B567E2909447868ABDDF500B78F2A3';可以很容易地概括.要补充的一点是，如果您的主要约束是两列或更多列，则此脚本不起作用...

Here a sample code to delete data from a parent table cascading to all child tables using the database_dictionary, I had lots of fun writing it ;-) Note the last line delete from person where pk = '38B567E2909447868ABDDF500B78F2A3'; can easily be generalised. Another thing to add, this script doesn't work if you have primary constraints of two columns or more...

declare 
  TYPE cur_typ IS REF CURSOR;
  procedure delete_from_sub_table_first(p_current_table_name varchar2, l_parent_key_value varchar2) is
     c cur_typ;
     child_table_pm_key_value varchar2(255);
  begin
    for childConsRecord in (select ac.table_name child_table, acc.column_name Child_column, rac.table_name, racc.COLUMN_NAME, (select column_name from ALL_CONS_COLUMNS accpm, all_constraints acpm where accpm.constraint_name = acpm.constraint_name and acpm.CONSTRAINT_TYPE = 'P' and ac.TABLE_NAME = acpm.TABLE_NAME) child_table_pm_key
                  from ALL_CONS_COLUMNS acc, all_constraints ac, ALL_CONS_COLUMNS racc, all_constraints rac
                  where acc.CONSTRAINT_NAME = ac.CONSTRAINT_NAME
                  and ac.CONSTRAINT_TYPE = 'R'
                  and racc.CONSTRAINT_NAME  = rac.CONSTRAINT_NAME
                  and rac.constraint_name = ac.R_CONSTRAINT_NAME
                  and rac.table_name = p_current_table_name) loop
      OPEN c FOR 'select ' || childConsRecord.child_table_pm_key || ' child_value FROM ' || childConsRecord.child_table || ' where ' || childConsRecord.Child_column || ' = :1' using l_parent_key_value;
      LOOP
          FETCH c INTO child_table_pm_key_value;
          EXIT WHEN c%NOTFOUND;
          -- process row here
          delete_from_sub_table_first(childConsRecord.child_table, child_table_pm_key_value);
      END LOOP;
      close c;
      EXECUTE IMMEDIATE 'DELETE FROM ' || childConsRecord.child_table || ' where ' || childConsRecord.Child_column || ' = :1' using l_parent_key_value;        
    end loop;
  end;
begin  
  delete_from_sub_table_first('PERSON', '38B567E2909447868ABDDF500B78F2A3');
  delete from person where pk = '38B567E2909447868ABDDF500B78F2A3';
end;
/

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