SELECT BYTES FROM USER_SEGMENTS WHERE SEGMENT_NAME = 'table_name_bad'; SELECT NUM_ROWS FROM USER_TABLES WHERE TABLE_NAME = 'table_name_bad'; 如何将上面两句SELECT语句结果集拼接为复合的SELECT语句?
时间: 2024-03-27 20:40:16 浏览: 13
你的问题中包含了SQL语句,我可以理解你想要将两个查询结果进行拼接。你可以使用UNION ALL关键字将两个SELECT语句的结果集进行拼接,例如:
```
SELECT BYTES, NULL AS NUM_ROWS FROM USER_SEGMENTS WHERE SEGMENT_NAME = 'table_name_bad'
UNION ALL
SELECT NULL AS BYTES, NUM_ROWS FROM USER_TABLES WHERE TABLE_NAME = 'table_name_bad';
```
这样,你就可以得到一个包含BYTES和NUM_ROWS两个列的结果集。需要注意的是,为了使两个结果集能够拼接,需要保证它们包含相同数量和类型的列。
相关问题
EDP_EDP_EXTERNAL_PLANT_REPORT_U_$RUN_DATE.dat与 SELECT BYTES FROM USER_SEGMENTS WHERE SEGMENT_NAME = 'table_name_bad';与 SELECT NUM_ROWS FROM USER_TABLES WHERE TABLE_NAME = 'table_name_bad'; 及$RUN_DATE 如何将上面语句结果集拼接为复合的SELECT语句并将结果用空格隔开?
以下是将上述语句结果集拼接为复合的SELECT语句并将结果用空格隔开的示例代码:
```
SELECT
EDP_EDP_EXTERNAL_PLANT_REPORT_U_$RUN_DATE.dat || ' ' || BYTES || ' ' || NUM_ROWS AS result
FROM
(SELECT
(SELECT COUNT(*) FROM USER_SEGMENTS WHERE SEGMENT_NAME = 'table_name_bad') AS BYTES,
(SELECT NUM_ROWS FROM USER_TABLES WHERE TABLE_NAME = 'table_name_bad') AS NUM_ROWS
FROM
dual)
CROSS JOIN
(SELECT TO_CHAR(SYSDATE, 'YYYYMMDD') AS $RUN_DATE FROM dual);
```
其中,EDP_EDP_EXTERNAL_PLANT_REPORT_U_$RUN_DATE.dat、table_name_bad和$RUN_DATE需要替换为实际的值。
EDP_EDP_EXTERNAL_PLANT_REPORT_U_$RUN_DATE.dat与 SELECT BYTES FROM USER_SEGMENTS WHERE SEGMENT_NAME = 'table_name_bad'; SELECT NUM_ROWS FROM USER_TABLES WHERE TABLE_NAME = 'table_name_bad'; 及$RUN_DATE 如何将上面查询语句结果集拼接为复合的SELECT语句并将结果用空格隔开?
以下是将查询语句结果集拼接为复合的SELECT语句并将结果用空格隔开的SQL语句:
```
SELECT LISTAGG(result, ' ') WITHIN GROUP (ORDER BY result_order) AS combined_results
FROM (
SELECT 'SELECT ' || bytes || ' FROM ' || segment_name || ';' AS result, 1 AS result_order
FROM USER_SEGMENTS
WHERE SEGMENT_NAME = 'table_name_bad'
UNION ALL
SELECT 'SELECT ' || num_rows || ' FROM ' || table_name || ';' AS result, 2 AS result_order
FROM USER_TABLES
WHERE TABLE_NAME = 'table_name_bad'
UNION ALL
SELECT '$RUN_DATE' AS result, 3 AS result_order
FROM dual
)
ORDER BY result_order;
```
其中,`USER_SEGMENTS`和`USER_TABLES`是Oracle系统表,用于查询表的信息,`dual`是Oracle系统表,用于查询常量。这个查询语句将三个查询结果拼接在一起,并用空格隔开,结果集中每一行都是一个完整的SELECT语句。其中,`$RUN_DATE`是作为一个常量插入到结果集中的,可以根据需要自行修改。