Excels SUMIF

The Microsoft Excel function sumif adds up cells that satisfy a condition:

Excel: =SUMIF(<source>, <condition>)

The same behavior can be obtained in SQL by using a case expression inside the sum function:

  SQL: SUM(CASE WHEN <condition> THEN <wert> 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: =SUMIF(Ax:Ay, 42)
  SQL: SUM(CASE WHEN A = 42 THEN A END)

The condition is not put under quotes—not even when using a comparison operator:

Excel: =SUMIF(Ax:Ay, "> 42")
  SQL: SUM(CASE WHEN A > 42 THEN A END)

The case expression accepts different values in the when and then branches. This allows you to do the same thing as the third argument of the sumif function.

Excel: =SUMIF(Ax:Ay, "> 42", Bx:By)
  SQL: SUM(CASE WHEN A > 42 THEN B END)

Text values, however, must be put under single quotes0:

Excel: =SUMIF(Ax:Ay, "Marvin", Bx:By)
  SQL: SUM(CASE WHEN A = 'Marvin' THEN B 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 sumif 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 sumif.

Excel: =SUMIFIF(Ax:Ay, "Marvin*", Bx:By)
  SQL: suM(CASE WHEN A LIKE 'Marvin%' THEN B END)

Sumif over multiple columns is done as the sum of one count function per column:

Excel: =SUMIF(Ax:Cy, 42)
  SQL: SUM(CASE WHEN A = 42 THEN A END) +
       SUM(CASE WHEN B = 42 THEN B END) +
       SUM(CASE WHEN C = 42 THEN C END)

The function Sumifs can often be implemented with an and condition in the case expression.

Excel: =SUMIFS(Bx:By, Ax:Ay, 42, Cx:Cy, 43)
  SQL: COUNT(CASE WHEN A = 42 AND C = 43 THEN B END)

More about this and related topics:

• The SQL case expression

• The filter clause in SQL

• The SQL null value

• Excel countif in SQL