Tag: sql server

PostgreSQL IN condition is used to reduce the need to use multiple OR conditions in SELECT, INSERT, UPDATE, or DELETE. The syntax for IN condition in PostgreSQL expression IN (value1_id,...

Before starting to create an SQL table, it is necessary to define the database model. Design an ER diagram in which to define the entities, attributes, and relationships. Basic...

Database security is a key factor for any application that includes very sensitive data, such as financial and health reports.Data protection can be achieved through encryption at various levels,...

PostgreSQL LIKE condition allows using wildcards (metacharacters) in WHERE proposal of SELECT, INSERT, UPDATE or DELETE operator. This allows for pattern matching. The syntax for the LIKE...

PostgreSQL condition OR is used to check two or more conditions under which records are returned when any of these conditions are met. It can be used in SELECT, INSERT, UPDATE, or DELETE...

PostgreSQL condition AND (also called AND operator) is used to check two or more conditions in SELECT, INSERT, UPDATE or DELETE operator. The syntax for the AND condition in PostgreSQL WHERE...

PostgreSQL Constraints: You'll learn how to create, add, and remove unique constraints in PostgreSQL with syntax and examples. What is a unique constraint in PostgreSQL? A unique constraint is...

PostgreSQL index: You will learn how to create, delete, and rename indexes in PostgreSQL with syntax and examples. What is an index in PostgreSQL? An index is a performance tuning method that...

You will learn how to create, drop, disable, and enable a primary key in PostgreSQL with syntax and examples. What is the primary key in PostgreSQL? In PostgreSQL, a primary key is a single...

You will learn how to create, update, and drop VIEWS in PostgreSQL with syntax and examples. What is VIEW in PostgreSQL? In PostgreSQL, VIEW is not a physical table, but rather a virtual table...

PostgreSQL TRUNCATE TABLE statement is used to remove (truncate) all records from a table or set of tables in PostgreSQL. It performs the same function as the DELETE operator, without the WHERE...

PostgreSQL DROP TABLE statement allows you to remove a table from a PostgreSQL database. The simplest syntax for DROP TABLE in PostgreSQL DROP TABLE table_name; The full syntax for the...

PostgreSQL ALTER TABLE statement is used to add, modify, or clear / delete columns in a table. PostgreSQL ALTER TABLE is also used to rename a table. Add a column to a table The syntax for...

   PostgreSQL CREATE TABLE AS statement is used to create a table from an existing table by copying columns of an existing table.It is important to note that when...

PostgreSQL CREATE TABLE statement allows you to create and define a table. The easiest syntax for CREATE TABLE statement in PostgreSQL CREATE TABLE table_name ( column1 datatype [ NULL | NOT...

PostgreSQL VACUUM statement is used to restore the storage by removing outdated data or tuples from a PostgreSQL database. The syntax for the VACUUM statement in PostgreSQL VACUUM [FULL]...