PostgreSQL – How to List all Tables

ByAdmin August 31, 2023August 31, 2023

To list all the tables in a PostgreSQL database, you can query the information_schema database which contains metadata about all the tables and other objects in the database.

Below is the SQL query you can use to show all the tables:

SELECT table_name 
FROM information_schema.tables 
WHERE table_schema = 'public';

This query will retrieve the names of all tables in the ‘public’ schema. If your tables are located in a different schema, you can replace 'public' with the appropriate schema name.

You can also use the pg_tables system catalog table to list all tables in the current database.

Here’s an example query to use the pg_tables catalog:

SELECT tablename 
FROM pg_tables 
WHERE schemaname = 'public';

This query retrieves the names of all tables in the ‘public’ schema. You can replace 'public' with the appropriate schema name if your tables are located in a different schema.

How-To Guides

PostgreSQL – How to Drop All Tables of a Schema

ByAdmin October 5, 2023October 5, 2023

To drop all tables in a PostgreSQL schema, you can use SQL queries or a combination of SQL queries and shell scripting. SELECT ‘DROP TABLE IF EXISTS “‘ || schemaname || ‘”.”‘ || tablename || ‘” CASCADE;’ FROM pg_tables WHERE schemaname = ‘your_schema_name’;

How-To Guides

PostgreSQL – How to Convert String to Date

ByAdmin August 31, 2023August 31, 2023

You can convert a string to a date using the TO_DATE function in PostgreSQL. This function allows you to specify the input string, the format of the string, and it will return a date accordingly. The general syntax of the TO_DATE function is as follows: TO_DATE(input_string, format_string) Here’s an example of using SELECT TO_DATE(‘2023-08-31’, ‘YYYY-MM-DD’);…

How-To Guides

PostgreSQL -How to Identify Duplicate Rows in PostgreSQL database

ByAdmin November 10, 2023November 10, 2023

To find duplicate values in a PostgreSQL table, you can use the GROUP BY clause along with the HAVING clause. Here is the syntax: SELECT column_name, COUNT(column_name) AS count FROM your_table GROUP BY column_name HAVING COUNT(column_name) > 1; where your_table is the actual name of your table and column_name is the column for which you…

How-To Guides

PostgreSQL – How to Get Current and Next Values of Sequence

ByAdmin September 5, 2023September 5, 2023

You can use Sequences to generate unique integer values, often used as auto-incrementing primary keys in tables. You can obtain the current value and the next value of a sequence using the currval and nextval functions, respectively. These functions are typically used within SQL statements or in PL/pgSQL code. Current Value (currval): To get the…

How-To Guides

PostgreSQL – How to Refresh a Materialized View

ByAdmin September 14, 2023September 14, 2023

You can refresh the data in a materialized view using the REFRESH MATERIALIZED VIEW statement in PostgreSQL database. A materialized view stores a snapshot of the data from the underlying tables, and this data can become stale over time. The REFRESH MATERIALIZED VIEW command allows you to update the materialized view with the latest data…

How-To Guides

PostgreSQL – How to Get the Last Day of Month From a Date

ByAdmin September 20, 2023September 20, 2023

To get the last day of the month from a date in PostgreSQL, you can use the DATE_TRUNC function in combination with some date arithmetic. Here’s how you can do it: SELECT (DATE_TRUNC(‘MONTH’, your_date_column) + INTERVAL ‘1 MONTH – 1 DAY’) AS last_day_of_month FROM your_table; where your_date_column is the name of your date column and…

Related

Similar Posts