The Microsoft Excel function countif
counts cells that satisfy a condition:
Excel: =COUNTIF(<source>, <condition>)
The same behavior can be obtained in SQL by using a case
expression inside the count
function:
SQL: COUNT(CASE WHEN <condition> THEN 1 END)
In Excel, the <source> defines arbitrary cells—Ax:Ay in the following examples. In SQL, the picking the rows is separate from the picking of the columns. The the group by
and over
clauses specify the rows. The column is explicitly used in the <condition>
that is put into the case
expression.
Excel: =COUNTIF(Ax:Ay, 42)
SQL: COUNT(CASE WHEN A = 42 THEN 1 END)
The condition is not put under quotes—not even when using a comparison operator:
Excel: =COUNTIF(Ax:Ay, "> 42")
SQL: COUNT(CASE WHEN A > 42 THEN 1 END)
Text values, however, must be put under single quotes0:
Excel: =COUNTIF(Ax:Ay, "Marvin")
SQL: COUNT(CASE WHEN A = 'Marvin' THEN 1 END)
Whether or not SQL text comparisons ignore case differences depends on the so-called collation. Even the default varies between database products: MySQL, MariaDB and SQL Server perform case-insensitive comparisons by default. PostgreSQL, the Oracle database and SQLite do—per default—take case differences into account.
Unlike the Excel countif
function, SQL does not apply wildcard matches when comparing strings with the equals sign (=
). To use wildcards in SQL, you have to use the like
operator. 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
.
Excel: =COUNTIF(Ax:Ay, "Marvin*")
SQL: COUNT(CASE WHEN A LIKE 'Marvin%' THEN 1 END)
Countif
over multiple columns is done as the sum of one count
function per column:
Excel: =COUNTIF(Ax:Cy, 42)
SQL: COUNT(CASE WHEN A = 42 THEN 1 END) +
COUNT(CASE WHEN B = 42 THEN 1 END) +
COUNT(CASE WHEN C = 42 THEN 1 END)
The function Countifs
can often be implemented with an and
condition in the case
expression.
Excel: =COUNTIFS(Ax:Ay, 42, Bx:By, 43)
SQL: COUNT(CASE WHEN A = 42 AND B = 43 THEN 1 END)
The function counta
can be implemented with a case
expression as well. For that, SQL makes a distinction between empty strings and the null
value. The following expression counts the rows that have neither the null
value or the empty string.
SQL: COUNT(CASE WHEN A IS NOT NULL AND A != '' THEN 1 END)
Note that the SQL equals operator (=
) cannot be used to check for the null value—you have to use is [not] null
instead.
More about this and related topics:
The SQL
case
expressionThe
filter
clause in SQLThe SQL
null
value