Template tag for EdgeQL

Proposal: provide a template tag for writing sanitized EdgeQL queries.

User input

import {edgeql} from "edgedb";

const query = edgeql`insert User { title := ${req.body.title}}`
// => { query: 'insert User { title := <str>$var_0 }', parameters: {var_0: "Some title"}}

We’d overload the query methods to support an object-based query format: {query: string; parameters: {[k:string]: any}}

await client.query(query)

The cast type will be inferred from the input data according to the following rules:

• Array.isArray(data) === true -> check that contents are homogenous primitives -> array<element-type>
• object -> json
• string -> str
• number -> float64
• bigint -> bigint
• boolean -> bool

Implicit/assignment casting makes this workable. e.g. Assigning a float64 to a int16 value will work without an explicit cast.

Identifiers

There should be a separate API for specifying identifiers: edgeql.ident(). This would verify that the input is a valid identifier with a regex.

import {edgeql, ident} from "edgedb";

const field1 = 'User'
const field2 = 'email'
edgeql`insert ${ident(field1)} { ${ident(field2)} };`

For convenience this function can be variadic. The inputs will be validated and joined with ", ".

edgeql`select User { ${ident('name', 'email')} }`
// select User { name, email }

### Prior art:

https://github.com/felixfbecker/node-sql-template-strings
https://github.com/blakeembrey/sql-template-tag
https://www.npmjs.com/package/pg-format

[haikyuu]

That’s virtually impossible to implement with just template literals

Indeed, but it would be possible with a VSCode extension. It would introspect each query at dev-time and tell typescript what type that is

[colinhacks]

No, this template tag will not be schema-aware nor can it infer types. That’s virtually impossible to implement with just template literals - you should use the query builder if you want inferred types and typechecking.