exportToSqlite3

Export Nim functions to your sqlite3 database instance without worrying about boilerplate code.

Installation

Add the package to your <project>.nimble file:

requires "exporttosqlite3 == 0.2.0"

Usage

import exporttosqlite3
import db_sqlite

proc myNimFunction(greeting: string, name: string, age: int32): string {.exportToSqlite3.} =
  greeting & " " & name & " (age " & $age & ")"

when isMainModule:
  let db = open("test.db", "", "", "")
  defer:
    db_sqlite.close(db)
  db.registerFunctions()
  db.exec(sql"DROP TABLE IF EXISTS students")
  db.exec(sql"CREATE TABLE students (name TEXT, age INT)")
  db.exec(sql"INSERT INTO students (name, age) VALUES (?, ?), (?, ?)",
      "Peter Parker", 23, "John Good", 19)
  db.exec(sql"UPDATE students SET name = myNimFunction('Hello', name, age)")

Supported data types

The following data types are supported for parameters and returns:

• cstring
• string (internally converted from/to cstring)
• int32
• int64
• float64
• float (alias for float64)
• bool (internally converted from/to int32)

Error handling

Exceptions are catched by the generated wrapper function and forwarded to sqlite through sqlite3_result_error. They can be catched as DbError in Nim, but only contain the original exception as a string representation.