Insert Into Third Table Based Two Another- 神谕

Question

我有这三个table；假设 table 的（尤其是 A）数据量非常大，我如何插入 Table C (c_table) FROM b_table 和 a_table :

Table乙：

CREATE TABLE b_table 
(
     NAME varchar2(10),
     ID number PRIMARY KEY
)

Table答：

CREATE TABLE a_table 
(
     CODE number,
     RATE number,
     DATEE date, 

     CONSTRAINT fk_a_table 
         FOREIGN KEY (CODE) REFERENCES b_table(ID)
);

Table C:

CREATE TABLE c_table 
(
     DATEE date,
     USD number, 
     EUR number,
     OBP number 
);

Answer 1

begin
for r in(
    with m as(
        select 1 as xcode, 1000 as xrate, sysdate as xdate from dual
        union all
        select 2, 2000, sysdate from dual
        union all
        select 3, 3000, sysdate-1 from dual
        union all
        select 1, 2000, sysdate from dual
        union all
        select 2, 4000, sysdate from dual
        union all
        select 3, 5000, sysdate-2 from dual
        )
        select * from m
                pivot(
                    sum(xrate) for xcode in (
                        1     as usd,
                        2     as eur,
                        3     as gbp
                        ))
)loop
    update your_table set foo = r.xrate, foo_currency_usd = x.usd where foo_date = r.date;
    end loop;
end;

Answer 2

试试下面的代码。

INSERT INTO c_table(DATEE, USD, EUR, OBP)
     Select DATEE, USD, EUR, OBP  from(
            Select 
              TO_CHAR(a.DATEE,'DD-MON-YYYY') DATEE, a.Rate, b.name from a_table a
            inner join b_table b on b.id=a.code
        )PIVOT(SUM(rate)for name in ('USD' USD, 'EUR' EUR,'OBP' OBP));

Answer 3

您可以使用条件聚合：

insert into c_table (DATEE, USD, EUR, OBP) 
    select a.DATEE,
           max(case WHEN a.code = 1 THEN a.rate end),
           max(case WHEN a.code = 2 THEN a.rate end),
           max(case WHEN a.code = 3 THEN a.rate end)
    from a_table a
    group by a.DATEE

Insert Into Third Table Based Two Another- 神谕

Insert Into Third Table Based Two Another- oracle

sql

oracle

sql-insert