Column Sets

Column sets are collections of columns you can reuse across multiple queries.

For convenience you can use the buildColumnSet() function to define your column types. This allows you to re-use the columns across queries without having to redefine them each time.

buildColumnSet() returns an object with functions you can use to add the columns to your query:

• get([col1], [col2]) - return specific columns
• getAll() - return all columns

Examples

Build a column set

import { buildColumnSet, columns } from "ts-query-model";

// define the columns we need. We'll use these across multiple queries
const columnSet = buildColumnSet({
  id: columns.number(),
  name: columns.string(),
  email: columns.string(),
});

The returned columnSet.get() function returns a set of columns for use in a query. It'll return the column for each name argument:

const exampleCols = columnSet.get("id", "email");
console.log(exampleCols);
// -> { id: NumberColumn, email: StringColumn }

Use columnSet.getAll() to use all the defined columns:

const exampleCols = columnSet.getAll();
console.log(exampleCols);
// -> { id: NumberColumn, name: StringColumn, email: StringColumn }

Use a column set in a query

Use the returned get() or getAll() function to provide the columns for a model definition:

const myAwesomeModel = {
  getThings: db.getMany({
    name: "get-all-things",
    // spread your column set here to add these columns to the query
    columns: columnSet.get("id", "email"),
    query: () => SQL`SELECT id, email FROM things`,
  }),
  getOnlyEmails: db.getMany({
    name: "get-only-email",
    // re-use the column set anywhere with different column names
    columns: columnSet.get("email"),
    query: () => SQL`SELECT id, email FROM things`,
  }),
};