Oracle数组

/*创建变长数组类型*/
CREATE TYPE t_varray_address AS VARRAY(3) OF VARCHAR2(50)
ALTER TYPE t_varray_address MODIFY LIMIT 10 CASCADE;
  /*创建嵌套表类型*/
   CREATE TYPE t_nested_table_address AS TABLE OF t_address
   CREATE TABLE customers_with_varray(
        id  INTEGER PRIMARY KEY,
        first_name VARCHAR2(10),
        last_name  VARCHAR2(10),
        addresses  t_varray_address
     )
    
     CREATE TABLE customers_with_nested_table(
          id  INTEGER PRIMARY KEY,
          first_name VARCHAR2(10),
          last_name  VARCHAR2(10),
          addresses  t_nested_table_address
     )
         NESTED TABLE
         addresses
         STORE AS
        nested_addresses
    
     /*获取变长数组类型*/
     DESCRIBE t_varray_address
     /*从user_varrays视图中检索出t_varray_address的详细信息*/
     SELECT parent_table_name,parent_table_column,type_name FROM user_varrays
     WHERE type_name='T_VARRAY_ADDRESS';
    
     SELECT table_name,table_type_name,parent_table_name,parent_table_column FROM user_nested_tables
     WHERE table_name='NESTED_ADDRESS'
     -------------
     /*填充变长数组元素*/
     ---------------
     INSERT INTO customers_with_varray VALUES(
     1,'Steve','Brown',
     t_varray_address(
     '2 State Street,Beantown,MA,12345',
     '4 Hill Street,Lost Town,CA,54321'
     )
     )
    
          INSERT INTO customers_with_varray VALUES(
     2,'John','Smith',
     t_varray_address(
     '1 High Street,Newtown,CA,12347',
     '3 New Street,AnyTown,MI,54323',
     '7 Market Street,Main Town,MA,54323'
     )
     )
     SELECT * FROM customers_with_varray
    

  /*填充嵌套表元素*/
     INSERT INTO customers_with_nested_table VALUES(
     1,'Steve','Brown',
     t_nested_table_address(
     t_address('2 State Street','Beantown','MA','12345'),
     t_address('4 Hill Street','Lost Town','CA','54321')
     )
    )
   
     INSERT INTO customers_with_nested_table VALUES(
     2,'John','Smith',
    t_nested_table_address(
     t_address('1 High Street','Newtown','CA','12347'),
     t_address('3 New Street','AnyTown','MI','54321'),
     t_address('7 Market Street','Main Town','MA','54323')
     )
    )
   
    SELECT * FROM customers_with_nested_table WHERE id=1
   
    SELECT a.*  FROM customers_with_nested_table c, TABLE(c.addresses) a  WHERE id = 1
   
    SELECT *    FROM TABLE (SELECT addresses  FROM customers_with_nested_table
    WHERE id = 1)
   
    SELECT c.id,c.first_name,c.last_name,a.* FROM customers_with_varray c,

   TABLE(c.addresses) a   WHERE id=1
    
      SELECT a.city,a.state   FROM customers_with_nested_table c, TABLE(c.addresses) a
     WHERE id = 1
    
     /*更改变长数组元素*/
     UPDATE customers_with_varray
     SET addresses=t_varray_address(
     '6 Any Street,Lost Town,GA,33347',
     '3 New Street,Anytown,MT,54323')
     WHERE id=2
     SELECT a.* FROM customers_with_varray c,TABLE(addresses) a WHERE id=2
   
    /*更改嵌套表元素*/
    UPDATE TABLE(
    SELECT addresses FROM customers_with_nested_table
    WHERE id=2
    ) addr
    SET VALUE(addr)=t_address('9 Any Street','Lost Town','VA','74321')
    WHERE VALUE(addr)=t_address('1 High Street','Newtown','CA','12347')
 

  EXPLAIN PLAN SET STATEMENT_ID='EXISTS_QUERY' FOR
   SELECT deptno,dname FROM dept WHERE EXISTS(
   SELECT deptno FROM dept WHERE loc='nanjing')

   SELECT XMLELEMENT("location",loc) AS XML_CITY
   FROM dept WHERE deptno=50