Function compileExpression

packages/powersync-db-collection/src/sqlite-compiler.ts:82–116

* Compiles a BasicExpression to a SQL string, mutating the params array.

(
  exp: IR.BasicExpression<unknown>,
  params: Array<unknown>,
  compileOptions?: CompileSQLiteOptions,
)

 * Compiles a BasicExpression to a SQL string, mutating the params array.
 */
function compileExpression(
  exp: IR.BasicExpression<unknown>,
  params: Array<unknown>,
  compileOptions?: CompileSQLiteOptions,
): string {
  switch (exp.type) {
    case `val`:
      params.push(exp.value)
      return `?`
    case `ref`: {
      if (exp.path.length !== 1) {
        throw new Error(
          `SQLite compiler doesn't support nested properties: ${exp.path.join(`.`)}`,
        )
      }
      const columnName = exp.path[0]!

      // PowerSync stores `id` as a top-level row column rather than inside the
      // JSON `data` object, so we skip json_extract. However, when compiling for
      // trigger WHEN clauses we still need the OLD./NEW. prefix. Extract it from
      // the jsonColumn option.
      if (compileOptions?.jsonColumn && columnName === `id`) {
        const prefix = compileOptions.jsonColumn.split('.')[0]!
        return `${prefix}.${quoteIdentifier(columnName)}`
      } else if (compileOptions?.jsonColumn) {
        return `json_extract(${compileOptions.jsonColumn}, '$.${columnName}')`
      }
      return quoteIdentifier(columnName)
    }
    case `func`:
      return compileFunction(exp, params, compileOptions)
    default:
      throw new Error(`Unknown expression type: ${(exp as any).type}`)
  }
}

/**
 * Compiles an OrderBy array to a SQL ORDER BY clause.