To remove the column we just created, enter this command: ALTER TABLE pg_equipment DROP COLUMN working_order; We can rename the entire table with this command: ALTER TABLE pg_equipment RENAME TO playground_equip; Deleting Tables in PostgreSQL We can delete the table we created by ...
InPostgreSQL, theALTER TABLEcommand performs different functionalities on a table. For example, theALTER TABLEstatement can add, drop, or update the table columns. Moreover, it allows us to add or remove constraints to a table. So, all in all, we can say that theALTER TABLEcommand is used...
How to Query Arrays How to Use string_agg() Database Management How to Create a Table How to Drop a Table How to Rename a Table How to Truncate a Table How to Duplicate a Table How to Add a Column How to Change a Column Name How to Add a Default Value How to Remove a Default ...
How to Delete a Column in SQL Database: Standard SQL MySQL PostgreSQL MS SQL Server Oracle Operators: ALTER TABLE DROP COLUMN Table of ContentsProblem Example Solution Discussion Problem You want to remove a column from a table. Example We would like to delete the column description ...
1. How do I extract a specific JSON key from a JSON column? You can use the->or->>operators to extract JSON keys.` `->returns the value as JSON, while->>returns the value as text. 2. Can I query nested JSON structures in PostgreSQL?
“ALTER COLUMN”commands, along with theTYPEKeyword, are used to change/modify the data type of a column. For example, integer to character, text to varchar, and so on. InPostgreSQL, we can change the data type of one or more than one column using the“ALTER TABLE”and“ALTER COLUMN”...
Modify existing rows in a table. Remove existing rows from a table. DML Statement Types INSERT UPDATE DELETE INSERT Statement You can add new rows to a table by using the INSERT statement: Syntax INSERTINTOtable[(column[,column...])]VALUES(value[,value...]); ...
How to Create PostgreSQL Views? Let us see how to create the views: Syntax: CREATE [OR REPLACE][TEMP OR TEMPORARY] [RECURSIVE] VIEW view_name [(column_name [, ...])] [ WITH (view_options_name [= view_options_value] [, ... ])] ...
Read More: How to Remove Column Headers in Excel Method 3 – Creating Column Headers by Formatting as a Table Steps: Choose the information you want to put into a table. Click the Insert tab and select the Table option. Check the My table has headers box and click OK. The first row ...
Not: MySQL, SQL Server, PostgreSQL The next method we’ll look at is using a subquery to identify and delete duplicate data. I’ll show you the query first, then explain how it works. DELETEFROMtablenameaWHEREa.rowid>ANY(SELECTb.rowidFROMtablenamebWHEREa.column1=b.column1); ...