For example, if the constant is a string, only string attributes, or attributes that are a subtype of string, are found.
| Constant Type | Comments |
|---|---|
| string | Enclose strings in single quotation marks. |
| integer | Integer values can be zero to +-2147483647. |
| boolean | Boolean values can be TRUE or FALSE. |
| time | Time values must be in the form time(’time_string’). See Date formats. |