如何在嵌套表中插入值而不丢失该表中的数据? [英] How to insert a value into a nested table without losing data in that table?

问题描述

如何将新数据插入现有行的嵌套表中?例如，我定义了

How can I insert new data into an existing row's nested table? For example, I have defined

CREATE OR REPLACE TYPE businessTableForCategories AS TABLE OF VARCHAR(128);
/

CREATE TABLE Category (
name                    VARCHAR(128) PRIMARY KEY,
businesses              businessTableForCategories
) NESTED TABLE businesses STORE AS categoryBusinessTable;

在类别中说一个带有name = 'Restaurant'和businesses = businessTableForCategories('xzqpehc234ajdpa8')的条目.

Say in Category there is an entry with name = 'Restaurant' and businesses = businessTableForCategories('xzqpehc234ajdpa8').

如何在不删除条目或丢失存储在嵌套表中的数据的情况下，将新数据插入该类别中该条目的嵌套表中?

How can I insert new data into that nested table for that entry in Category without removing the entry, or losing the data stored in the nested table?

我问，因为我要插入的条目之一要求插入语句的长度为25137个字符，这超出了Oracle对单个命令的限制.这是因为该类别中有许多企业.我想创建类别，然后将业务一个接一个(或可能是小的分组)插入嵌套表"businesses"中.

I ask because one of the entries I am trying to insert requires an insert statement that is 25137 characters long, which is way past Oracle's limit for a single command. This is because there are many businesses in the category. I would like to create the category, and then insert the businesses one by one (or maybe small groupings) into the nested table "businesses".

推荐答案

使用MULTISET UNION [ALL|DISTINCT]运算符:

SQL小提琴

Oracle 11g R2架构设置:

CREATE OR REPLACE TYPE businessTableForCategories AS TABLE OF VARCHAR(128);
/

CREATE TABLE Category (
name                    VARCHAR(128) PRIMARY KEY,
businesses              businessTableForCategories
) NESTED TABLE businesses STORE AS categoryBusinessTable
/

INSERT INTO Category VALUES (
  'Restaurant',
  businessTableForCategories('xzqpehc234ajdpa8')
)
/

UPDATE Category
SET businesses = businesses
                 MULTISET UNION ALL 
                 businessTableForCategories('other_value')
WHERE name = 'Restaurant'
/

查询1 :

SELECT *
FROM   category

结果 :

Results:

|       NAME |                   BUSINESSES |
|------------|------------------------------|
| Restaurant | xzqpehc234ajdpa8,other_value |

查询2 :

或使用绑定变量将集合包括在查询中:

Or use a bind variable to include the collection in the query:

DECLARE
  businesses businessTableForCategories := businessTableForCategories();
BEGIN
  businesses.EXTEND( 10000 );
  FOR i IN 1 .. 10000 LOOP
    businesses(i) := DBMS_RANDOM.STRING( 'x', 128 );
  END LOOP;
  INSERT INTO Category VALUES ( 'lots of data', businesses );
END;

查询3 :

SELECT name, CARDINALITY( businesses )
FROM   Category

结果 :

Results:

|         NAME | CARDINALITY(BUSINESSES) |
|--------------|-------------------------|
| lots of data |                   10000 |
|   Restaurant |                       2 |

这篇关于如何在嵌套表中插入值而不丢失该表中的数据?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！