将 SQL Server T-SQL 转换为 SQL

Question

我一直在尝试使用pivot 从表格中获取特定视图的代码。

create table temp
(
    date datetime,
    category varchar(3),
    amount money
)

insert into temp values ('1/1/2012', 'ABC', 1000.00)
insert into temp values ('2/1/2012', 'DEF', 500.00)
insert into temp values ('2/1/2012', 'GHI', 800.00)
insert into temp values ('2/10/2012', 'DEF', 700.00)
insert into temp values ('3/1/2012', 'ABC', 1100.00)


DECLARE @cols AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX);

SET @cols = STUFF((SELECT distinct ',' + QUOTENAME(c.category) 
            FROM temp c
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

set @query = 'SELECT date, ' + @cols + ' from 
            (
                select date
                    , amount
                    , category
                from temp
           ) x
            pivot 
            (
                 max(amount)
                for category in (' + @cols + ')
            ) p '


execute(@query)

drop table temp

declare 语句中出现错误，并且pivot 未被 dbviz SQL 指挥官识别为关键字

我什至删除了@并尝试运行它，但我无法成功执行

我正在使用 Oracle Database 11g（oracle JDBC 驱动程序）

Answer 1

如果您尝试从 SQLPlus 或 SQLcl 运行此代码，您可以使用下面的代码在 Oracle 中生成相同的信息。

Oracle 19c 及更高版本

在 Oracle 19 中，Oracle 引入了执行 LISTAGG(DISTINCT <value>) 的功能，从而无需执行子查询来删除任何重复项。

CREATE TABLE temp
(
    date_val    DATE,
    category    VARCHAR (3),
    amount      NUMBER
);

INSERT INTO temp
     VALUES (DATE '2012-01-01', 'ABC', 1000.00);

INSERT INTO temp
     VALUES (DATE '2012-02-01', 'DEF', 500.00);

INSERT INTO temp
     VALUES (DATE '2012-02-01', 'GHI', 800.00);

INSERT INTO temp
     VALUES (DATE '2012-02-10', 'DEF', 700.00);

INSERT INTO temp
     VALUES (DATE '2012-03-01', 'ABC', 1100.00);

column category_list NEW_VALUE categories

SELECT '''' || LISTAGG (DISTINCT category, ''',''') WITHIN GROUP (ORDER BY category) || ''''    AS category_list
  FROM temp;

SELECT *
  FROM (SELECT date_val, amount, category FROM temp) x
       PIVOT (MAX (amount) FOR category IN (&categories)) p;

DROP TABLE temp;

早于 Oracle 19c

CREATE TABLE temp
(
    date_val    DATE,
    category    VARCHAR (3),
    amount      NUMBER
);

INSERT INTO temp
     VALUES (DATE '2012-01-01', 'ABC', 1000.00);

INSERT INTO temp
     VALUES (DATE '2012-02-01', 'DEF', 500.00);

INSERT INTO temp
     VALUES (DATE '2012-02-01', 'GHI', 800.00);

INSERT INTO temp
     VALUES (DATE '2012-02-10', 'DEF', 700.00);

INSERT INTO temp
     VALUES (DATE '2012-03-01', 'ABC', 1100.00);

column category_list NEW_VALUE categories

SELECT '''' || LISTAGG (category, ''',''') WITHIN GROUP (ORDER BY category) || ''''    AS category_list
  FROM (SELECT DISTINCT category
          FROM temp);

SELECT *
  FROM (SELECT date_val, amount, category FROM temp) x
       PIVOT (MAX (amount) FOR category IN (&categories)) p;

DROP TABLE temp;

任一脚本的结果

SQL> @test_tsql_conversion.sql


Table TEMP created.


1 row inserted.


1 row inserted.


1 row inserted.


1 row inserted.


1 row inserted.


       CATEGORY_LIST
____________________
'ABC','DEF','GHI'


old:SELECT *
  FROM (SELECT date_val, amount, category FROM temp) x
       PIVOT (MAX (amount) FOR category IN (&categories)) p
new:SELECT *
  FROM (SELECT date_val, amount, category FROM temp) x
       PIVOT (MAX (amount) FOR category IN ('ABC','DEF','GHI')) p

    DATE_VAL    'ABC'    'DEF'    'GHI'
____________ ________ ________ ________
01-FEB-12                  500      800
10-FEB-12                  700
01-JAN-12        1000
01-MAR-12        1100


Table TEMP dropped.

Answer 2

基于 EJ Egyed 的回答，这里有一个 PL/SQL 版本：

declare
    cols   long;
    query  long;
    results sys_refcursor;
begin
    select '''' || listagg(category||''' as "'||upper(category)||'"', ', ''') within group (order by category)
    into   cols
    from   (select distinct category from temp);

    query :=
    'select * from 
     ( select dt, amount, category
       from temp ) x
     pivot 
     ( max(amount) for category in ('||cols||') ) p';

    open results for query;
    dbms_sql.return_result(results);
end;

解决方案将根据您希望如何执行代码而有所不同。 dbms_sql.return_result 会将结果集传递给 12c 或更高版本的客户端，例如 SQL*Plus 或 SQL Developer，但可能无法与 DbVisualizer 或 Tableau 等第三方工具一起使用。 SQL*Plus 是 Oracle 的基本命令行工具，主要用于管理和部署脚本，但并不真正适合最终用户报告。 SQL Developer 是一个程序员的 IDE，业务分析师可能会使用它，但它同样不适合一般最终用户。

最通用的方法可能是将其编写为返回一个引用的过程，然后可以由用 Java、C# 等编写的应用程序处理。

过程版本如下所示：

create or replace procedure pivot_categories
    ( out_results out sys_refcursor )
as
    cols   long;
    query  long;
begin
    select '''' || listagg(category||''' as "'||upper(category)||'"', ', ''') within group (order by category)
    into   cols
    from   (select distinct category from temp);

    query :=
    'select * from 
     ( select dt, amount, category
       from temp ) x
     pivot 
     ( max(amount) for category in ('||cols||') ) p';

    open out_results for query;
end pivot_categories;

Answer 3

这是你需要的：

create table temp
(
    date timestamp(3),
    category varchar2(3),
    amount number
);

insert into temp values ('1/1/2012', 'ABC', 1000.00)
insert into temp values ('2/1/2012', 'DEF', 500.00)
insert into temp values ('2/1/2012', 'GHI', 800.00)
insert into temp values ('2/10/2012', 'DEF', 700.00)
insert into temp values ('3/1/2012', 'ABC', 1100.00)


 v_cols NVARCHAR(MAX);
    v_query  NVARCHAR(MAX);

SELECT STUFF((SELECT distinct ',' || QUOTENAME(c.category) 
            FROM temp c
            FOR INTO v_cols FROM dual XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

v_query := 'SELECT date, ' || v_cols || ' from 
            (
                select date
                    , amount
                    , category
                from temp
           ) x
            pivot 
            (
                 max(amount)
                for category in (' || v_cols || ')
            ) p '


execute immediate v_query

drop table temp

还有一个在线sql转换工具：http://www.sqlines.com/online