gliderecord-patterns（滑翔记录模式）

GlideRecord Best Practices for ServiceNow

GlideRecord is the primary API for database operations in ServiceNow. Following these patterns ensures efficient and secure queries.

Basic Query Patterns

Get Single Record by sys_id

var gr = new GlideRecord("incident")
if (gr.get("sys_id_here")) {
  gs.info("Found: " + gr.getValue("number"))
}

Get Single Record by Field

var gr = new GlideRecord("sys_user")
if (gr.get("user_name", "admin")) {
  gs.info("Found user: " + gr.getValue("name"))
}

Query Multiple Records

var gr = new GlideRecord("incident")
gr.addQuery("active", true)
gr.addQuery("priority", "1")
gr.orderByDesc("sys_created_on")
gr.setLimit(100)
gr.query()

while (gr.next()) {
  gs.info(gr.getValue("number"))
}

Encoded Queries (Faster)

Use encoded queries for complex conditions - they're more efficient than multiple addQuery calls:

var gr = new GlideRecord("incident")
// Encoded query from list view URL or Query Builder
gr.addEncodedQuery("active=true^priority=1^assigned_toISEMPTY")
gr.query()

while (gr.next()) {
  // Process records
}

Performance Tips

1. Always Use setLimit()

// When you only need X records
var gr = new GlideRecord("incident")
gr.addQuery("active", true)
gr.setLimit(10) // Don't fetch more than needed
gr.query()

2. Use getValue() for Strings

// CORRECT - Returns string value
var number = gr.getValue("number")

// ALSO WORKS but returns GlideElement
var element = gr.number
var numberStr = gr.number.toString()

3. Use getDisplayValue() for References

// Get the display value of a reference field
var assignedToName = gr.getDisplayValue("assigned_to")

// Get the sys_id of a reference field
var assignedToId = gr.getValue("assigned_to")

4. Avoid Queries in Loops

// BAD - Query inside loop
for (var i = 0; i < userIds.length; i++) {
  var gr = new GlideRecord("sys_user")
  gr.get(userIds[i]) // N queries!
}

// GOOD - Single query with IN clause
var gr = new GlideRecord("sys_user")
gr.addQuery("sys_id", "IN", userIds.join(","))
gr.query()
while (gr.next()) {
  // Process all users at once
}

5. Use GlideAggregate for Counts

// BAD - Counting with GlideRecord
var count = 0
var gr = new GlideRecord("incident")
gr.addQuery("active", true)
gr.query()
while (gr.next()) {
  count++
}

// GOOD - Use GlideAggregate
var ga = new GlideAggregate("incident")
ga.addQuery("active", true)
ga.addAggregate("COUNT")
ga.query()
if (ga.next()) {
  var count = ga.getAggregate("COUNT")
}

CRUD Operations

Insert

var gr = new GlideRecord("incident")
gr.initialize()
gr.setValue("short_description", "New incident")
gr.setValue("caller_id", gs.getUserID())
gr.setValue("priority", "3")
var sysId = gr.insert()

Update

var gr = new GlideRecord("incident")
if (gr.get("sys_id_here")) {
  gr.setValue("state", "6") // Resolved
  gr.setValue("close_notes", "Issue fixed")
  gr.update()
}

Delete (Use with Caution!)

var gr = new GlideRecord("incident")
if (gr.get("sys_id_here")) {
  gr.deleteRecord()
}

Bulk Update

var gr = new GlideRecord("incident")
gr.addQuery("state", "6") // Resolved
gr.addQuery("resolved_at", "<", gs.daysAgoStart(30))
gr.query()

while (gr.next()) {
  gr.setValue("state", "7") // Closed
  gr.update()
}

Query Operators

Security Considerations

1. setWorkflow(false) - Skip business rules for bulk operations
2. setLimit() - Prevent runaway queries
3. Check canRead()/canWrite() - Verify ACL permissions
4. Never trust user input - Validate before using in queries