Interface and types for example queries

(cherry picked from commit b7b87bc)

src/main/metabase/examples.ts

@@ -0,0 +1,66 @@
+import { Table } from './types';
+
+/** An example query card. */
+type ExampleQuery = {
+  name: string; // Title of card.
+  sql: string; // SQL query.
+  sizeX: number; // Grid of 18 units wide.
+  sizeY: number; // Height of card in units.
+  display: 'table' | 'bar' | 'row' | 'scalar' | 'map'; // Other types TBD.
+  visualizationSettings: Record<string, unknown>; // To be typed later.
+
+  // There's also row/col properties, but we'll make some rectangle
+  // packing algorithm to arrange cards automatically in a section.
+};
+
+/** A section for a group of examples. */
+type ExamplesSection = {
+  title: string | null; // Markdown text as the section heading.
+  queries: ExampleQuery[]; // Cards in section.
+};
+
+function lines(...lines: string[]) {
+  return lines.join('\n');
+}
+
+export function exampleQueries(table: Table, aidColumns: string[]): ExamplesSection[] {
+  const { fields, display_name } = table; // TODO: iterate and inspect fields
+
+  let name = table.name;
+  // if (requiresQuoting(name)) {
+  //   name = `"${name}"`
+  // }
+
+  // const t = getT('example-queries'); // Let's worry about i18n later...
+
+  return [
+    {
+      title: 'Overview',
+      queries: [
+        {
+          name: `Count of ${display_name}`,
+          sql: lines('SELECT count(*)', `FROM ${name}`),
+          sizeX: 6, // 6 is a good default (3 cards per row).
+          sizeY: 4, // 4 is a good default.
+          display: 'scalar',
+          visualizationSettings: {}, // No visualizations for now. To be done after we finish SQL.
+        },
+      ],
+    },
+    {
+      // GROUP BY examples
+      title: `Distribution of ${display_name}`,
+      queries: [
+        {
+          name: `${display_name} by <column>`,
+          sql: lines('SELECT <column>, count(*)', `FROM ${name}`, 'GROUP BY <column>'),
+          sizeX: 6,
+          sizeY: 4, // For a table we might need something taller.
+          display: 'table', // For now we show results only as 'table'.
+          visualizationSettings: {},
+        },
+      ],
+    },
+    // ...
+  ];
+}

src/main/metabase/types.ts

@@ -0,0 +1,98 @@
+/*
+ * API response types extracted from sample responses and metabase source.
+ * Fields that we don't care about are commented out or marked as unknown.
+ */
+
+type ISO8601Time = string;
+
+export type Table = {
+  description: string;
+  entity_type: string;
+  schema: string;
+  // db: unknown;
+  show_in_getting_started: boolean;
+  name: string;
+  fields: Field[];
+  // caveats: unknown;
+  // segments: unknown[];
+  dimension_options: Record<number, unknown>;
+  updated_at: ISO8601Time;
+  active: boolean;
+  id: number;
+  db_id: number;
+  // visibility_type: unknown;
+  // field_order: unknown;
+  initial_sync_status: string;
+  display_name: string;
+  // metrics: unknown[];
+  created_at: ISO8601Time;
+  // points_of_interest: unknown;
+};
+
+export type TextFieldFingerprint = {
+  'percent-json': number;
+  'percent-url': number;
+  'percent-email': number;
+  'percent-state': number;
+  'average-length': number;
+};
+
+export type NumberFieldFingerprint = {
+  avg: number;
+  max: number;
+  min: number;
+  q1: number;
+  q3: number;
+  sd: number;
+};
+
+export type DateTimeFieldFingerprint = {
+  earliest: ISO8601Time;
+  latest: ISO8601Time;
+};
+
+export interface FieldFingerprint {
+  global: {
+    'distinct-count'?: number;
+    'nil%': number;
+  };
+  type?: {
+    'type/Text'?: TextFieldFingerprint;
+    'type/Number'?: NumberFieldFingerprint;
+    'type/DateTime'?: DateTimeFieldFingerprint;
+  };
+}
+
+export type Field = {
+  description: string | null;
+  database_type: string; // See https://github.com/metabase/metabase/blob/master/src/metabase/driver/postgres.clj#L504-L566
+  semantic_type: string | null; // See https://github.com/metabase/metabase/blob/master/shared/src/metabase/types.cljc
+  // coercion_strategy: unknown;
+  name: string;
+  fingerprint_version: number;
+  // has_field_values: string;
+  // settings: unknown;
+  // caveats: unknown;
+  // fk_target_field_id: unknown;
+  // dimensions: unknown[];
+  dimension_options: string[];
+  updated_at: ISO8601Time;
+  // custom_position: number;
+  effective_type: string;
+  active: boolean;
+  // nfc_path: unknown;
+  // parent_id: unknown;
+  id: number;
+  last_analyzed: ISO8601Time;
+  position: number;
+  visibility_type: 'details-only' | 'hidden' | 'normal' | 'retired';
+  // default_dimension_option: unknown;
+  // target: unknown;
+  preview_display: boolean;
+  display_name: string;
+  database_position: number;
+  fingerprint: FieldFingerprint;
+  created_at: ISO8601Time;
+  base_type: string;
+  // points_of_interest: unknown;
+};