Category Archives: postgresql

Khóa học miễn phí PostgreSQL – Functions nhận dự án làm có lương

PostgreSQL – Functions PostgreSQL functions, also known as Stored Procedures, allow you to carry out operations that would normally take several queries and round trips in a single function within the database. Functions allow database reuse as other applications can interact directly with your stored procedures instead of a middle-tier or duplicating code. Functions can […]

Khóa học miễn phí PostgreSQL – Unions Clause nhận dự án làm có lương

PostgreSQL – UNIONS Clause The PostgreSQL UNION clause/operator is used to combine the results of two or more SELECT statements without returning any duplicate rows. To use UNION, each SELECT must have the same number of columns selected, the same number of column expressions, the same data type, and have them in the same order […]