将APC 评论中的纯 SQL 解决方案与Oracle 12 中的增强功能相结合,以允许在子句中声明函数以及Kaushik Nayak用于将字符串值转换为日期的方法,然后您可以得到:WITH
EXECUTE IMMEDIATE
Oracle 设置 - 测试表和数据:
CREATE TABLE EXPORT_TABLE (
TABLE_OWNER VARCHAR2(30),
TABLE_NAME VARCHAR2(30),
PARTITION_NAME VARCHAR2(30),
HIGH_VALUE LONG,
NUM_ROWS INTEGER
);
INSERT INTO EXPORT_TABLE VALUES ( 'TO', 'TN', 'PN', 'TIMESTAMP ''2019-06-26 12:34:56''', 12345 );
查询:
WITH FUNCTION clobToDate( value IN CLOB ) RETURN DATE
IS
ts DATE;
BEGIN
EXECUTE IMMEDIATE 'BEGIN :ts := ' || value || '; END;' USING OUT ts;
RETURN ts;
END;
SELECT TABLE_OWNER,
TABLE_NAME,
PARTITION_NAME,
clobToDate(
EXTRACTVALUE(
dbms_xmlgen.getxmltype(
'SELECT high_value'
|| ' FROM EXPORT_TABLE'
|| ' WHERE TABLE_OWNER = ''' || t.table_owner || ''''
|| ' AND TABLE_NAME = ''' || t.table_name || ''''
|| ' AND PARTITION_NAME = ''' || t.partition_name || ''''
),
'//text()'
)
) AS HIGH_VALUE,
NUM_ROWS
FROM EXPORT_TABLE t;
输出:
表所有者 | 表名 | PARTITION_NAME | 高值 | NUM_ROWS
:------------ | :--------- | :------------- | :----------------- | --------:
到 | 田纳西州 | PN | 2019-06-26 12:34:56 | 12345
db<>在这里摆弄
更新:如果你想聚合一些列,那么:
WITH FUNCTION clobToDate( value IN CLOB ) RETURN DATE
IS
ts DATE;
BEGIN
EXECUTE IMMEDIATE 'BEGIN :ts := ' || value || '; END;' USING OUT ts;
RETURN ts;
END;
SELECT table_owner,
table_name,
MAX( high_value ) AS max_high_value,
SUM( num_rows ) AS total_rows
FROM (
SELECT TABLE_OWNER,
TABLE_NAME,
PARTITION_NAME,
clobToDate(
EXTRACTVALUE(
dbms_xmlgen.getxmltype(
'SELECT high_value'
|| ' FROM EXPORT_TABLE'
|| ' WHERE TABLE_OWNER = ''' || t.table_owner || ''''
|| ' AND TABLE_NAME = ''' || t.table_name || ''''
|| ' AND PARTITION_NAME = ''' || t.partition_name || ''''
),
'//text()'
)
) AS HIGH_VALUE,
NUM_ROWS
FROM EXPORT_TABLE t
)
GROUP BY table_owner, table_name;
db<>在这里摆弄