Grammar Reference

EBNF Grammar

Expression ::= SelectExpr | InsertExpr | UpdateExpr | DeleteExpr

SelectExpr ::= "select" "*" "from" Ident FilterOrWhere? OrderBy? Limit?
             | "select" Ident "{" ShapeFields "}" FilterOrWhere? OrderBy? Limit?
             | "select" Ident FilterOrWhere? OrderBy? Limit?

InsertExpr ::= "insert" Ident "{" Assignments "}"

UpdateExpr ::= "update" Ident FilterClause? "set" "{" Assignments "}"

DeleteExpr ::= "delete" Ident FilterClause?

FilterOrWhere ::= "filter" Condition
                | "where" Condition

OrderBy ::= "order" "by" Ident ("asc" | "desc")?

Limit ::= "limit" Number

ShapeFields ::= ShapeField ("," ShapeField)*

ShapeField ::= Ident
             | Ident ":" "{" ShapeFields "}"

Assignments ::= Assignment ("," Assignment)*

Assignment ::= Ident ":=" Literal

Condition ::= TermCondition (BinaryOp TermCondition)*

TermCondition ::= Literal
                | Ident
                | "(" Condition ")"

BinaryOp ::= "=" | "!=" | ">" | ">=" | "<" | "<="

Literal ::= Number | "true" | "false" | String

Number ::= [0-9]+

Ident ::= [a-zA-Z_][a-zA-Z0-9_]*

String ::= '"' [^"]* '"'

Keywords

The following are reserved keywords in BQL:

Keyword	Usage
select	Query data
insert	Add new records
update	Modify existing records
delete	Remove records
filter	Add conditions (BQL style)
where	Add conditions (SQL style)
set	Specify update values
order	Sort results
by	Used with order
asc	Ascending order
desc	Descending order
limit	Limit result count
from	Specify table (with *)
true	Boolean literal
false	Boolean literal

Syntax Notes

Shape Syntax { }

Used to specify which fields to select or what values to set:

-- SELECT: fields to return
select User { id, name, email }

-- INSERT: field assignments
insert User { name := "Alice", email := "a@b.com" }

-- UPDATE: fields to modify
update User filter id = 1 set { name := "Bob" }

Assignment Operator :=

Used in INSERT and UPDATE to assign values:

name := "Alice"
count := 42
active := true

Filter vs Where

Both work identically - filter is BQL style, where is SQL style:

-- These are equivalent
select User { name } filter id = 1
select User { name } where id = 1