Like is a special comparison operator that can be used to compare two text values. You can use wildcards on the right side of the operator to define a pattern to be matched. The comparison is case sensitive. The following table shows the wildcards that you can use.

If you want to match one of the wildcard characters, precede the character with a backslash (\).

These examples are based on the Museum sample data set and show how you would use the LIKE operator in mrScriptBasic or mrScriptMetadata. In SQL queries, enclose text strings in single quotation marks ' ' instead of double quotation marks " ".

address is a text variable that records respondents' addresses. The Like operator in this example compares whether the value in the variable contains the text “London” in any position. For example, you could use this expression to select respondents who have the word “London” anywhere in their address. However, this expression would include respondents who live, for example, in London House in New York and would exclude respondents who have London spelled with any other combination of upper and lower case characters (such as LONDON or london) or misspelled (such as Londoon).

The percent sign has been removed from the end of the pattern. The expression now selects respondents only if the word “London” is at the end of their address. In fact there are no respondents who have the word “London” at the end of their address in the Museum sample, because all of the London addresses end with the area code.

Now the pattern includes an underscore wildcard followed by the letter “S” and the percent wildcard. The underscore wildcard matches any single character, so this expression selects respondents who have the word “London” followed by an upper case “S” with any one character in between. For example, this expression would select respondents with the following addresses:

However, it would not select respondents with the following addresses:

The first of these is excluded because there are two characters between the word “London” and the character “S”. The second is excluded because the “s” is not uppercase.

The search is case sensitive when you use the RDB DSC 2 or when the LIKE keyword is included in a complex expression (for example, one that includes a function from the UNICOM Intelligence Function Library). For more information, see What's new in the Relational MR database CDSC.