Question

我想显示以下数据的数据透视表。我有一张包含10000条记录的表格。

表：Mat_test

CREATE TABLE Mat_test AS
SELECT DISTINCT 1 + floor(random() * 1500000)::integer AS id,
                2 + floor(random() * 1600000)::integer AS Numbers
FROM   generate_series(1, 10000) g;

现在创建一个函数，我想从中显示上述记录的交叉表：

功能：Mat_test_cross_tab

CREATE OR REPLACE FUNCTION Mat_test_cross_tab (_retType anyelement
                                             , table_name varchar)
  RETURNS SETOF anyelement AS
$BODY$
DECLARE
    query varchar;
    cols varchar;
    cols1 varchar;
    cols2 varchar;
BEGIN
    cols := 'SELECT string_agg(numbers::varchar,'','') from '||table_name||'';
    execute cols into cols1;

    cols1 := 'SELECT REPLACE('''||cols1||''','','','' " INT,"'')';
    execute cols1 into cols2;

    cols2 := '"'||cols2||'" INT';
    raise info '%',cols2;

    query := 'SELECT * FROM Crosstab
         (
          '' SELECT id,numbers,count(*) as t
             from '||table_name||'
             group by 1,2
             order by 1,2'',
             $$select distinct numbers from '||table_name||'$$
          )
          AS (id integer,'||cols2')';

    RAISE INFO '%',query;

    RETURN QUERY EXECUTE query;

END;
$BODY$  LANGUAGE PLPGSQL;

现在我正在创建用于创建用户定义类型的函数，以返回上述函数的结果集。

功能：Type_mat

CREATE OR REPLACE FUNCTION Type_mat(table_name varchar)
  RETURNS VOID AS
$BODY$
DECLARE 
    query varchar;
    cols varchar;
    cols1 varchar;
    cols2 varchar;
BEGIN
    cols := 'SELECT string_agg(numbers::varchar,'','') from '||table_name||'';
    execute cols into cols1;

    cols1 := 'SELECT REPLACE('''||cols1||''','','',''" INT,"'')';
    execute cols1 into cols2;
    cols2 := '"'||cols2||'" INT';

    query := 'CREATE TYPE Type_for_mat AS
         (
            id integer,
            '||cols2||'
          )';

    RAISE INFO '%',query;

    EXECUTE query;
END;
$BODY$  LANGUAGE PLPGSQL;

呼叫：

SELECT Type_mat('mat_test');

收到错误：

ERROR: tables can have at most 1600 columns

PostgreSQL 9.3：巨大记录的动态数据透视表

0 个答案: