What is LIMIT Clause and How Does it Work in PostgreSQL?
LIMIT is an optional clause in PostgreSQL that is executed with a SELECT query to fetch only specific/limited records from a table.
What is DELETE CASCADE and How it Works in PostgreSQL?
“DELETE CASCADE” feature in Postgres ensures referential integrity by automatically deleting all child records when the corresponding parent record is deleted.
PostgreSQL NOW() Function | Check/Get Current Date and Time
The NOW() function returns the current date and time along with the time zone information. The returned data type of this function is “TIMESTAMPTZ”.
How to Find/Check Database and Table Size in PostgreSQL
To find the database and table sizes in PostgreSQL, the pg_database_size() and the pg_relation_size() functions are used, respectively.
How To Describe a Table in PostgreSQL
To describe tables in PostgreSQL, the “\dt”, “\dt+” or the “\d tab_name” meta-commands and “information_schema” are used.
How to Find String Length in PostgreSQL
In PostgreSQL, the length of the string can be found by using functions like LENGTH(), OCTET_LENGTH(), and BIT_LENGTH().
Understanding DATE Data Type in PostgreSQL
To create a DATE type column, specify the column’s name followed by the DATE keyword. By default, the DATE data type stores data in “YYYY-MM-DD” format.
PostgreSQL UPDATE – How to Update Table Rows
To update the table values/data in PostgreSQL, the UPDATE command is used. This statement allows the user to update the previous data to new data values.
PostgreSQL SELECT – How to Select Table Records
In PostgreSQL, the SELECT statement is used with the FROM clause to get/fetch the required result from the specified table.
How to Rename the table in PostgreSQL
To rename a table in PostgreSQL, use the ALTER TABLE statement along with the RENAME TO clause. A table can be renamed manually using pgAdmin.
PostgreSQL INSERT – How to Insert New Rows into a Table
To insert values/rows into a Postgres table, use the INSERT INTO statement. The VALUE clause is used to specify the values that need to be inserted.
How to Add Primary Key Constraint to a Column in PostgreSQL
In Postgres, a Primary key can be added to a column during table creation. It can be added to an existing table using the ALTER TABLE ADD CONSTRAINT command.
PostgreSQL DELETE – How to Delete Table Rows
In PostgreSQL, the DELETE statement is used with the FROM clause to delete a single, multiple, or all rows of a specific table.
How to Create a Table in Postgres
To create a table in PostgreSQL, execute the CREATE TABLE statement either in pgAdmin or in psql. Postgres tables can also be created manually using pgAdmin.
How to Create a Database in Postgres
To create a database in PostgreSQL, execute the “CREATE DATABASE” command in the SQL Shell or pgAdmin. Users can also create databases manually using pgAdmin
How to Drop Columns From a Table in PostgreSQL
To drop/delete a column from a PostgreSQL table, we can use the ALTER TABLE statement and the DROP COLUMN clause together.
How to Drop a Table in Postgres
Execute the DROP TABLE command either in SQL Shell or in pgAdmin to drop a particular table in Postgres. A table can also be dropped manually using pgAdmin.
How to Switch a Database in Postgres
To switch a database in Postgres, execute the “\c db_name” or “\connect db_name” command in psql. Or you can switch a database manually using pgAdmin.
