SQL: COUNT(CASE WHEN A IS NOT NULL AND A != '' THEN 1 END) The following expression counts the rows that have neither the null value or the empty string. For that, SQL makes a distinction between empty strings and the null value. The function counta can be implemented with a case expression as well. SQL: COUNT(CASE WHEN A = 42 AND B = 43 THEN 1 END) The function Countifs can often be implemented with an and condition in the case expression. SQL: COUNT(CASE WHEN A = 42 THEN 1 END) + SQL: COUNT(CASE WHEN A LIKE 'Marvin%' THEN 1 END)Ĭountif over multiple columns is done as the sum of one count function per column: Excel: =COUNTIF( Ax: Cy, 42) The like operator uses underscore ( _) as a wildcard for a single character and the percent sign ( %) as the wildcard for any number of characters-like ? and * in Excels countif. To use wildcards in SQL, you have to use the like operator. Unlike the Excel countif function, SQL does not apply wildcard matches when comparing strings with the equals sign ( =). PostgreSQL, the Oracle database and SQLite do-per default-take case differences into account. Even the default varies between database products: MySQL, MariaDB and SQL Server perform case-insensitive comparisons by default. Whether or not SQL text comparisons ignore case differences depends on the so-called collation. SQL: COUNT(CASE WHEN A = 'Marvin' THEN 1 END) Text values, however, must be put under single quotes 0: Excel: =COUNTIF( Ax:Ay, "Marvin") The condition is not put under quotes-not even when using a comparison operator: Excel: =COUNTIF(Ax:Ay, "> 42") The column is explicitly used in the that is put into the case expression. The the group by and over clauses specify the rows. In SQL, the picking the rows is separate from the picking of the columns. In Excel, the defines arbitrary cells-Ax:Ay in the following examples. The same behavior can be obtained in SQL by using a case expression inside the count function: SQL: COUNT(CASE WHEN THEN 1 END) In other words, you can remove duplicate values in the calculation.įor examples of this see How to Remove Duplicates from SQLite Count() Results.The Microsoft Excel function countif counts cells that satisfy a condition: Excel: =COUNTIF(, ) You can add the DISTINCT keyword to count only distinct values. One handy use case for count() is to use it in conjunction with the GROUP BY clause, so that multiple rows are returned – each one representing a group – with a count of the rows in that group. SELECT count(Fax)īut you can do something like this instead: SELECT count(Fax) The result is not calculated after any LIMIT clause. So we can see that only rows 1 and 5 have non-NULL values in the Fax column. Here’s what the results look like with columns returned (and without using the count() function). In this case, there were only two non-NULL values in the Fax column within the result set. The result of count() is calculated after any WHERE clauses. In other words, 47 rows contain a NULL value in the Fax column. In this case, the Fax column has 12 non-NULL values. In this example, I pass the name of a specific column of the table. I ran this query on the Chinook sample database, and so it turns out that there are 59 rows in the Customer table. Here’s a basic example to demonstrate the asterisk (*) syntax to return the number of rows in a table. So in this case, X could be the name of a column, and the asterisk ( *) wildcard is used to specify the total number of rows in the group. If you provide the name of a column, it will return the number of times that column is not NULL. If you pass in the asterisk ( *) wildcard character, it will return the total number of rows in the group. It can also be used to return the number of times a given column is not NULL in the result set. The SQLite count() function can be used to return the number of rows in a result set.
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