![]() ![]() (note that it doesn't matter which constant value to use as a count() function's parameter, be it *, 0 or 1 or anything - all works the same as long as it's a constant as opposed to the field name. SELECT count (*) FROM goods WHERE category_id = 1 Instead, you should always ask your database to count the rows and then return the only number, with a query like this: SELECT count ( 1 ) FROM users Monitoring PostgreSQL with Navicat Monitor 3.When you need to count rows that match some criteria in your database, under no circumstances you should select the actual rows and then use rowCount()!.Trace Queries on your PostgreSQL Instances with Navicat Monitor 3.Viewing PostgreSQL Instance Details in Navicat Monitor 3.A Quick Guide to Naming Conventions in SQL - Part 2.A Quick Guide to Naming Conventions in SQL - Part 3.Selecting Distinct Values From a Relational Database.Implement Audit Trail Logging Using Triggers.Multi-Version Concurrency Control in PostgreSQL. ![]()
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