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 […]
Category Archives: postgresql
PostgreSQL – NULL Values The PostgreSQL NULL is the term used to represent a missing value. A NULL value in a table is a value in a field that appears to be blank. A field with a NULL value is a field with no value. It is very important to understand that a NULL value […]
PostgreSQL – Operators What is an Operator in PostgreSQL? An operator is a reserved word or a character used primarily in a PostgreSQL statement”s WHERE clause to perform operation(s), such as comparisons and arithmetic operations. Operators are used to specify conditions in a PostgreSQL statement and to serve as conjunctions for multiple conditions in a […]