Search results for: "query count"

What is the difference between using COUNT(typeid) and COUNT(*) in a SQL query in PHP?

When using COUNT(typeid), the query will only count the rows where the typeid column is not null. On the other hand, using COUNT(*) will count all row...

What is the difference between using COUNT(*) and COUNT(column) in a MySQL query for counting posts in PHP?

When counting posts in a MySQL query in PHP, using COUNT(*) will count all rows in a table regardless of null values in the specified column, while us...

What are the differences between using "Count" and "Count(distinct)" in a PHP MySQL query, and when should each be used?

When using "Count" in a MySQL query, it will count all rows that match the specified condition, including duplicates. On the other hand, "Count(distin...

What are the potential pitfalls of using COUNT(*) in a SQL query when trying to count the number of tables in a database?

Using COUNT(*) in a SQL query to count the number of tables in a database can be misleading because it will count all rows in the system tables, not j...

In what scenarios would using a SELECT query with mysql_num_rows be more efficient than using a COUNT query in MySQL when working with PHP?

Using a SELECT query with mysql_num_rows can be more efficient than using a COUNT query in MySQL when you need to retrieve the actual rows of data alo...