Question

I want to fetch data using my python code like we do with describe [tableName] statement . I want to do that on Redshift and DB2.

I tried to do that using Pandas and cursors, I tried the following chunks of commands:

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

2. describe schema.tableName

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

4. \\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()

I want the output as following:

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

Answer 1

A lot of this data is included in the SVV_COLUMNS system view. You can query that table using the table_name and table_schema columns.

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