SQL – Delete Table Table of content The SQL DELETE is a command of Data Manipulation Language (DML), so it does not delete or modify the table structure but it delete only the data contained within the table. Therefore, any constraints, indexes, or triggers defined in the table will still exist after you delete data […]

SQL – Constraints Table of content SQL Constraints SQL Constraints are the rules applied to a data columns or the complete table to limit the type of data that can go into a table. When you try to perform any INSERT, UPDATE, or DELETE operation on the table, RDBMS will check whether that data violates […]

SQL – ALTER TABLE Table of content SQL − ALTER TABLE Statement The SQL ALTER TABLE command is a part of Data Definition Language (DDL) and modifies the structure of a table. The ALTER TABLE command can add or delete columns, create or destroy indexes, change the type of existing columns, or rename columns or […]