Calculated Transactions

Fluree supports computed values in transactions using the bind clause. This enables atomic read-modify-write operations like incrementing counters, applying discounts, or computing derived values—all within a single transaction.

The Problem

Without calculated transactions, updating a value like an inventory count requires multiple steps:

Query the current value (e.g., 100)
Calculate the new value in your application code (100 - 1 = 99)
Issue a transaction with the hard-coded value (99)

This creates a race condition: if another transaction modifies the value between steps 1 and 3, your update will overwrite it with stale data.

The Solution: BIND in Transactions

Fluree's bind clause computes values atomically within the transaction itself:

{
  "@context": { "ex": "http://example.org/" },
  "ledger": "inventory",
  "where": [
    { "@id": "?product", "ex:sku": "ABC123", "ex:inventory": "?qty" },
    ["bind", "?newQty", "(- ?qty 1)"]
  ],
  "delete": { "@id": "?product", "ex:inventory": "?qty" },
  "insert": { "@id": "?product", "ex:inventory": "?newQty" }
}

The where clause binds the current value, bind computes the new value, and delete/insert perform the atomic update—all in one transaction with no race conditions.

BIND Syntax

The bind clause uses a tuple format within the where array:

["bind", "?variableName", "(expression)"]

Expressions use prefix notation (Lisp-style):

Expression	Result
`(+ 1 2)`	`3`
`(- 10 3)`	`7`
`(* 2 3 4)`	`24`
`(/ 100 4)`	`25`
`(power 2 8)`	`256`
`(+ ?a (* ?b 2))`	`a + (b * 2)`

Built-in Functions

Fluree provides 60+ built-in functions for use in BIND expressions.

Arithmetic

Function	Alias	Example	Result
`plus`	`+`	`(+ 1 2 3)`	`6`
`minus`	`-`	`(- 10 3)`	`7`
`multiply`	`*`	`(* 2 3 4)`	`24`
`divide`	`/`	`(/ 100 4)`	`25`
`power`		`(power 2 8)`	`256`
`quotient`	`quot`	`(quot 17 5)`	`3`
`absolute-value`	`abs`	`(abs -5)`	`5`

Numeric

Function	Example	Result
`ceil`	`(ceil 4.2)`	`5`
`floor`	`(floor 4.8)`	`4`
`round`	`(round 4.5)`	`5`
`min`	`(min 3 1 4)`	`1`
`max`	`(max 3 1 4)`	`4`

Aggregates

Function	Description
`sum`	Sum of values
`avg`	Average
`median`	Median value
`variance`	Variance
`stddev`	Standard deviation
`count`	Count values
`count-distinct`	Count unique values
`sample`	Random sample

String

Function	Example	Result
`concat`	`(concat "Hello" " " "World")`	`"Hello World"`
`strLen`	`(strLen "Hello")`	`5`
`subStr`	`(subStr "Hello" 0 2)`	`"He"`
`ucase`	`(ucase "hello")`	`"HELLO"`
`lcase`	`(lcase "HELLO")`	`"hello"`
`strStarts`	`(strStarts "Hello" "He")`	`true`
`strEnds`	`(strEnds "Hello" "lo")`	`true`
`contains`	`(contains "Hello" "ell")`	`true`
`strBefore`	`(strBefore "Hello" "l")`	`"He"`
`strAfter`	`(strAfter "Hello" "l")`	`"lo"`
`replace`	`(replace "Hello" "l" "L")`	`"HeLLo"`
`regex`	`(regex "test123" "[0-9]+")`	`true`

Date/Time

Function	Description
`now`	Current timestamp
`year`	Extract year
`month`	Extract month
`day`	Extract day
`hours`	Extract hours
`minutes`	Extract minutes
`seconds`	Extract seconds
`tz`	Extract timezone

Cryptographic

Function	Description
`sha256`	SHA-256 hash
`sha512`	SHA-512 hash

Logic & Comparison

Function	Alias	Example
`and`	`&&`	`(and true false)` → `false`
`or`	`\|\|`	`(or true false)` → `true`
`not`	`!`	`(not true)` → `false`
`=`		`(= 1 1)` → `true`
`!=`		`(!= 1 2)` → `true`
`<`		`(< 1 2)` → `true`
`<=`		`(<= 1 1)` → `true`
`>`		`(> 2 1)` → `true`
`>=`		`(>= 1 1)` → `true`
`bound`		`(bound ?x)` → is variable bound?
`coalesce`		`(coalesce ?x ?y 0)` → first non-null

RDF/Type Functions

Function	Description
`datatype`	Get datatype IRI
`lang`	Get language tag
`isNumeric`	Check if numeric
`isBlank`	Check if blank node
`is-iri`	Check if IRI
`is-literal`	Check if literal
`uuid`	Generate UUID
`struuid`	Generate UUID as string
`bnode`	Generate blank node

Vector/ML Functions

Function	Description
`dotProduct`	Vector dot product
`cosineSimilarity`	Cosine similarity
`euclidianDistance`	Euclidean distance

Practical Examples

Decrement Inventory

Atomically reduce inventory by 1:

{
  "@context": { "ex": "http://example.org/" },
  "ledger": "inventory",
  "where": [
    { "@id": "?product", "ex:sku": "ABC123", "ex:inventory": "?qty" },
    ["bind", "?newQty", "(- ?qty 1)"]
  ],
  "delete": { "@id": "?product", "ex:inventory": "?qty" },
  "insert": { "@id": "?product", "ex:inventory": "?newQty" }
}

Increment Counter

Atomically increment a page view counter:

{
  "@context": { "ex": "http://example.org/" },
  "ledger": "analytics",
  "where": [
    { "@id": "?counter", "ex:name": "page-views", "ex:count": "?n" },
    ["bind", "?newCount", "(+ ?n 1)"]
  ],
  "delete": { "@id": "?counter", "ex:count": "?n" },
  "insert": { "@id": "?counter", "ex:count": "?newCount" }
}

Apply Percentage Discount

Apply a 20% discount to all items on sale:

{
  "@context": { "ex": "http://example.org/" },
  "ledger": "products",
  "where": [
    { "@id": "?item", "ex:price": "?price", "ex:onSale": true },
    ["bind", "?salePrice", "(* ?price 0.8)"]
  ],
  "insert": { "@id": "?item", "ex:salePrice": "?salePrice" }
}

Compute Full Name from Parts

Concatenate first and last names:

{
  "@context": { "ex": "http://example.org/" },
  "ledger": "people",
  "where": [
    { "@id": "?person", "ex:firstName": "?first", "ex:lastName": "?last" },
    ["bind", "?fullName", "(concat ?first \" \" ?last)"]
  ],
  "insert": { "@id": "?person", "ex:fullName": "?fullName" }
}

Complex Mathematical Expression

Compute a complex formula:

{
  "@context": { "ex": "http://example.org/" },
  "ledger": "data",
  "where": [
    { "@id": "?s", "ex:num": "?num" },
    ["bind", "?result", "(* (power (- (/ (+ ?num 10) 2) 3) 3) 5 2)"]
  ],
  "insert": { "@id": "?s", "ex:result": "?result" }
}

This computes: ((((num + 10) / 2) - 3) ^ 3) * 5 * 2

Set Default Value with Coalesce

Set a default value if a property is missing:

{
  "@context": { "ex": "http://example.org/" },
  "ledger": "inventory",
  "where": [
    { "@id": "?item", "ex:name": "?name" },
    ["optional", { "@id": "?item", "ex:quantity": "?existingQty" }],
    ["bind", "?qty", "(coalesce ?existingQty 0)"]
  ],
  "insert": { "@id": "?item", "ex:quantity": "?qty" }
}

Add Timestamp to Records

Add a last-modified timestamp:

{
  "@context": { "ex": "http://example.org/" },
  "ledger": "records",
  "where": [
    { "@id": "?record", "ex:status": "updated" },
    ["bind", "?timestamp", "(now)"]
  ],
  "insert": { "@id": "?record", "ex:lastModified": "?timestamp" }
}

Generate Unique IDs

Generate a UUID for new records:

{
  "@context": { "ex": "http://example.org/" },
  "ledger": "orders",
  "where": [
    ["bind", "?orderId", "(struuid)"]
  ],
  "insert": {
    "@id": "?orderId",
    "@type": "ex:Order",
    "ex:createdAt": { "@value": "2024-01-15T10:30:00Z", "@type": "xsd:dateTime" }
  }
}

Conditional Updates with If

Apply different logic based on conditions:

{
  "@context": { "ex": "http://example.org/" },
  "ledger": "accounts",
  "where": [
    { "@id": "?account", "ex:balance": "?balance", "ex:type": "?type" },
    ["bind", "?fee", "(if (= ?type \"premium\") 0 5)"],
    ["bind", "?newBalance", "(- ?balance ?fee)"]
  ],
  "delete": { "@id": "?account", "ex:balance": "?balance" },
  "insert": { "@id": "?account", "ex:balance": "?newBalance" }
}

Combining BIND with Filters

You can filter which records to update based on computed values:

{
  "@context": { "ex": "http://example.org/" },
  "ledger": "inventory",
  "where": [
    { "@id": "?product", "ex:inventory": "?qty", "ex:reorderPoint": "?reorder" },
    ["bind", "?newQty", "(- ?qty 1)"],
    ["filter", "(< ?newQty ?reorder)"]
  ],
  "insert": { "@id": "?product", "ex:needsReorder": true }
}

This marks products for reorder when inventory falls below the reorder point.

Limitations

No shorthand operators: No ++ or -- syntax; use (+ ?x 1) or (- ?x 1)
No triggers: Calculations don't run automatically; must be explicit in transactions
No custom functions: Limited to built-in functions
Prefix notation only: Must use (+ 1 2) not 1 + 2

Transaction Syntax - Full transaction reference
FlureeQL Query Syntax - BIND in queries
Vector Search - Using vector functions

The Problem​

The Solution: BIND in Transactions​

BIND Syntax​

Built-in Functions​

Arithmetic​

Numeric​

Aggregates​

String​

Date/Time​

Cryptographic​

Logic & Comparison​

RDF/Type Functions​

Vector/ML Functions​

Practical Examples​

Decrement Inventory​

Increment Counter​

Apply Percentage Discount​

Compute Full Name from Parts​

Complex Mathematical Expression​

Set Default Value with Coalesce​

Add Timestamp to Records​

Generate Unique IDs​

Conditional Updates with If​

Combining BIND with Filters​

Limitations​

Related Resources​