POSTGRESQL：选择特定类型的列时创建表

我有一个混合数据类型（实数、整数、字符…）的表，但我只恢复具有实数值的列

我可以构建这个：

SELECT 'SELECT ' || array_to_string(ARRAY(
select 'o' || '.' || c.column_name 
from information_schema.columns as c
where table_name = 'final_datas'
and c.data_type = 'real'), ',') || ' FROM final_datas as o' As sqlstmt

因此：

"SELECT o.random,o.struct2d_pred2_num,o.pfam_num,o.transmb_num [...] FROM final_datas as o"

我想用这些列创建一个表。当然，这样做是行不通的：

create table table2 as (
SELECT 'SELECT ' || array_to_string(ARRAY(
select 'o' || '.' || c.column_name 
from information_schema.columns as c
where table_name = 'final_datas'
and c.data_type = 'real'), ',') || ' FROM final_datas as o' As sqlstmt
)

---

建议？

您需要将整个CREATE TABLE语句生成为动态SQL：

SELECT 'CREATE TABLE table2 AS SELECT ' || array_to_string(ARRAY(
select 'o' || '.' || c.column_name 
from information_schema.columns as c
where table_name = 'final_datas'
and c.data_type = 'real'), ',') || ' FROM final_datas as o' As sqlstmt

---

可以使用

executesqlstmt运行结果
您需要将整个CREATETABLE语句生成为动态SQL：

SELECT 'CREATE TABLE table2 AS SELECT ' || array_to_string(ARRAY(
select 'o' || '.' || c.column_name 
from information_schema.columns as c
where table_name = 'final_datas'
and c.data_type = 'real'), ',') || ' FROM final_datas as o' As sqlstmt

可以使用
executesqlstmt运行结果
查看pg_目录以了解此信息。运行
psql-E
，然后在其中运行
\d final_data
，您将看到需要运行的相关查询。查看pg_目录以了解此信息。运行
psql-E
，然后在其中运行
\d final_data
，您将看到需要运行的相关查询。