获取数据库表蓝图，例如从 redshift 获取“describe table_name”命令，从 python 获取 DB2

Posted 2023-03-31

【中文标题】获取数据库表蓝图，例如从 redshift 获取“describe table_name”命令，从 python 获取 DB2

【英文标题】：Fetch DB tables blueprint like "describe table_name" commande from redshift and DB2 from python

【发布时间】：2019-01-01 12:48:47

【问题描述】：

我想像使用describe [tableName] statement 一样使用我的python 代码获取数据。我想在 Redshift 和 DB2 上这样做。

我尝试使用 Pandas 和游标来做到这一点，我尝试了以下命令块：

"set search_path to SCHEMA; select * from pg_table_def where schemaname = 'schema' and LOWER(tablename) = 'TableName';

describe schema.tableName

select column_name, data_type, character_manimum_length from information_schema.columns where table_schema = 'Schema' and table_name = 'TableName';

\d or \d+

.

import psycopg2
import numpy as np
import pandas as pd   



con=psycopg2.connect(dbname= 'DBNAME', host="Host-Link",
    port= '5439', user= 'username', password= 'password')
    print(con)

cur = con.cursor()
query  = "set search_path to Schema; select * from pg_table_def where schemaname = 'Schema' and LOWER(tablename) = 'TableName';"
cur.execute(query)
temp = cur.fetchall()
print(temp)

data_frame = pd.read_sql("set search_path to Schema; select * from pg_table_def where schemaname = 'Schema' and LOWER(tablename) = 'TableName';", con)
print(data_frame)

con.close()

我希望输出如下：

COLUMN_NAME DATA_TYPE   PK  NULLABLE    DEFAULT AUTOINCREMENT   COMPUTED    REMARKS POSITION
col1        varchar(10) YES NO            NO          NO           1
col2        varchar(50) NO  NO            NO          NO           2
col3        smallint    NO  NO            NO          NO           3

【参考方案1】：

很多此类数据都包含在SVV_COLUMNS 系统视图中。您可以使用table_name 和table_schema 列查询该表。

https://docs.aws.amazon.com/redshift/latest/dg/r_SVV_COLUMNS.html