Why do we use count (*)?

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The question is "Why would you use count('foo')? " The answer is that the writer wants to count rows and inject a bit of individuality into .mysql - Should I COUNT(*) or not? - Stack OverflowIs that good to wrap a sql query to do a row count queryCount number of rows without using any aggregate functionsIs using COUNT(*) or SELECT * a good idea? - Stack OverflowДругие результаты с сайта stackoverflow.com

When can we use count (*)?

COUNT (1) means it will return a single value among the total number of records. COUNT (*) means it will return all values among the total number of records.

Should I use count (*)?

In general, you should always use COUNT(*). This is because the database can often count rows by accessing an index, which is much faster than accessing a table. If you use COUNT(column), the database must actually inspect the individual values in the column, since it will not count NULLs.

What does count (*) mean in SQL?

COUNT(*) returns the number of rows in a specified table, and it preserves duplicate rows. It counts each row separately. This includes rows that contain null values.

What is the difference between count and count (*)?

As you've already learned, COUNT(*) will count all the rows in the table, including NULL values. On the other hand, COUNT(column name) will count all the rows in the specified column while excluding NULL values.

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