Filtering empty or blank values
Sometimes, rows display nothing for a particular column. For example, suppose a customer database table contains an e-mail field. Some customers, however, do not supply an e-mail address. In this case, the e-mail field might contain an empty value or a blank value. An empty value, also called a null value, means no value is supplied. Null values apply to all data types. You can create a filter to exclude data rows where a particular column has null values.
When filtering to exclude null values, use the Is Not Null operator. To view only rows that have null values in a particular column, use Is Null, or in the Value field, select No Value. For example, the following filter condition excludes customer data where the e-mail column contains null values:
email Is Not Null
The following filter condition displays only rows where the e-mail column contains null values:
email Is Null

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