Postgresql Where Boolean Is True, 以上查询将返回”employees”表中年龄大于30或已婚的员工记录。 使用布尔函数进行条件查询 除了使用布尔表达式，PostgreSQL 还提供了一些布尔函数，用于在查询中检查布尔值的真假结果。 1. Boolean Type PostgreSQL provides the standard SQL type boolean; see Table 8-19. Note: The SQL supports TRUE, How to count, how may true and false for the field public in postgresql user table i have tried this query select sum (case when false then 1 else 0 end) as false, sum (case when true then 1 else Each condition (condition1, condition2, condition3 ) is a Boolean expression that returns true or false. You'll learn how to use the PostgreSQL BOOL_AND() aggregate function to return true if all values in a set of values are true. This tutorial explains how to display Boolean values as either TRUE or FALSE in PostgreSQL, including an example. The condition must evaluate to true, false, or unknown. 21. 4 The standard way to insert boolean values in PostgreSQL is to use the literal boolean values true or false or any expression that evaluates to a boolean. 論理値データ型 PostgreSQL では、標準の SQL の型 boolean が提供されています。 boolean は 2 つしかない値のどちらかを取ることができます。「真（true）」または「偽（false）」です。 第 3 PostgreSQL provides the SQL99 type boolean. In this article, we will explain the PostgreSQL BOOLEAN data type and its implementation in database table design, highlighting its usage This tutorial explains how to display Boolean values as either TRUE or FALSE in PostgreSQL, including an example.