MySQL - Subtract (-) Operator

The MySQL - (subtract) operator is used to subtract two values. It operates on numerical values.

The example below describes how to use subtract operator in various conditions:

Example:

Consider a database table called Sample with the following records:

• Using with WHERE Clause: To select records of table where difference of Var1 and Var2 column values is greater than 20, the query is given below.

  SELECT * FROM Sample
  WHERE Var1 - Var2 > 20;
  

  
  

  The query will produce following result:

  Data	Var1	Var2
  Data4	25	4
  Data5	30	5
  Data6	35	6

• Using with AS Clause: The difference of Var1 and Var2 column values can be displayed in a different column using AS clause:

  SELECT *, (Var1 - Var2) AS Diff FROM Sample;
  

  
  

  The query will produce following result:

  Data	Var1	Var2	Diff
  Data1	10	1	9
  Data2	15	2	13
  Data3	20	3	17
  Data4	25	4	21
  Data5	30	5	25
  Data6	35	6	29

• Using with UPDATE Clause: To update the column Var1 with the difference of columns Var1 and Var2, the query is given below:

  UPDATE Sample
  SET Var1 = Var1 - Var2;
  
  --See result
  SELECT * FROM Sample;
  

  
  

  The query will produce following result:

  Data	Var1	Var2
  Data1	9	1
  Data2	13	2
  Data3	17	3
  Data4	21	4
  Data5	25	5
  Data6	29	6

• Using with values: To subtract two values, we can simply use SELECT statement:

  SELECT 50 - 30;
  

  
  

  The query will produce following result:

  50 - 30
  20