Category Archives: sql

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 […]

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 – Operators Table of content What is SQL Operator? An SQL operator is a reserved word or a character used primarily in an SQL statement”s WHERE clause to perform operation(s), such as comparisons and arithmetic operations. These Operators are used to specify conditions in an SQL statement and to serve as conjunctions for multiple […]