GlideRecord addQuery with null string value returns no results - Support and Troubleshooting

GlideRecord addQuery with null string value returns no results Issue .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } When a field is set to a literal string value of 'null' and a query is made using gr.addQuery(field_name, 'null') , the query returns no results instead of returning the record. This occurs because ServiceNow interprets the string 'null' passed to addQuery() differently from an actual database null value. The expected behavior is that one record is returned for the field containing the literal string value 'null'; the actual behavior is that the query returns zero records.

This can be replicated in a base system by importing the attached XML record, which creates a record in the cmdb_ci_ip_address table with a value of 'null' in the dns_domain field. Running the following script on that record reproduces the issue:

var gr = new GlideRecord('cmdb_ci_ip_address'); // Returns 0 when this is uncommented, but 1 when it is gr.addQuery('dns_domain', 'null'); gr.query(); gs.print("@@111"); gs.print(gr.getRowCount()); gs.print("@@222"); while ( gr.next() ) { gs.print("@@333"); // gs.print(gr.sys_id); gs.print("@@444"); } Expected result: One record returned where the field contains a null value.

Actual result: The query with a 'null' string parameter returns no records.

Release .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } Any

Cause .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } Using the string 'null' as a literal field value is not supported behavior in ServiceNow — it results in clearing the field rather than storing the string. Because 'null' is a reserved word in ServiceNow scripts, calling gr.addQuery(field_name, 'null') does not query for records where the field contains the literal text 'null'; instead, it is interpreted as a null (empty) check, producing unexpected results.

The root cause is that the field contains a data integrity issue: the value stored is a literal string 'null' rather than a true database NULL. The SQL trace for this scenario shows the correct output:

SELECT cmdb0.`sys_id` FROM cmdb cmdb0 WHERE cmdb0.`sys_class_path` = '/!!/!Y' AND cmdb0.`dns_domain` IS NULL Resolution .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } Use addNullQuery() with correct data

gr.addNullQuery() is the supported method for null checks. When the field value is a true database NULL (not the string 'null'), this method works as expected. To correct the data and use this method:

Locate the affected record in the cmdb_ci_ip_address table and change the dns_domain field value from the string 'null' to a true NULL (empty) value. Save the record. Update the query script to use gr.addNullQuery() as follows: var gr = new GlideRecord('cmdb_ci_ip_address'); gr.addNullQuery('dns_domain'); gr.query(); gs.print(gr.getRowCount());

Another option would be using addQuery() with the IN operator.

Use the following syntax to return records where the field contains the literal string 'null':

gr.addQuery('dns_domain', 'IN', 'null'); This approach returns the correct result without requiring a data change.

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