While applying a filter to a string column, wildcards can be useful. They are used along with the LIKE operator. Wildcards help to substitute one or more characters in a string. We can define a string format using patterns, for example, email ID. They can be considered similar to regular expressions used in other programming languages. Following are some of the common wildcards used –  Symbol  Description  Pattern  Match  %  Represents zero or more characters  %n  John, Alan  _  Represents a single character  s_t  set, sit  []  Represents atleast one match in the brackets  c[a-z0-9]  color, cr7  ^  Represents characters expect the ones’ mentioned in the brackets  STU[0-9]  STU001, STU999