@opengis/bi/server/routes/dataset/controllers/dbTablePreview.js

BI data visualization module

import { pgClients } from "@opengis/fastify-table/utils.js";

const q = `select nspname||'.'||relname as table, json_agg(json_build_object('name',attname, 'type', a.atttypid::regtype, 'description', coalesce(col_description(attrelid, attnum),attname))) as columns
from pg_attribute a
left join pg_catalog.pg_attrdef d ON (a.attrelid, a.attnum) = (d.adrelid, d.adnum)
JOIN pg_class AS i
  ON i.oid = a.attrelid 
JOIN pg_namespace AS NS ON i.relnamespace = NS.OID
where a.attnum > 0 and nspname||'.'||relname = $1
and not a.attisdropped
group by nspname||'.'||relname limit 1`;

export default async function dbTablePreview({ pg = pgClients.client, params = {}, query = {} }) {
  if (!params?.name) {
    return { message: 'not enough params: name', status: 400 };
  }

  if (query.sql) return q;
  try {
    const { table, columns } = await pg
      .query(q, [params.name.replace(/"/g, '')])
      .then(el => el.rows?.[0] || {});
    if (!table) {
      return { message: 'table not found', status: 404 };
    }

    const { count = 0 } = await pg.query('select reltuples as count from pg_class where oid  = to_regclass($1)', [params.name])
      .then(el => el.rows?.[0] || {});
    const geom = columns.find((el) => el.type === 'geometry')?.name;
    const { bounds, extentStr } = geom
      ? await pg.query(`select 
        count(*),
        st_asgeojson(st_extent(${geom}))::json as bounds,
        replace(regexp_replace(st_extent(${geom})::box2d::text,'BOX\\(|\\)','','g'),' ',',') as "extentStr"
      from ${params.name}`).then(el => el.rows?.[0] || {})
      : {};
    const extent = extentStr ? extentStr.split(',') : undefined;

    const systemColumns = [
      'uid',
      'files',
      'editor_date',
      'cdate',
      'editor_id',
      geom,
    ];

    const columnList = columns.map((el) => el?.name).filter((el) => !systemColumns.includes(el));
    const { rows = [] } = await pg.query(`select ${columnList.map(el => `"${el.replace(/'/g, "''")}"`).join(',')} ${geom ? ', st_asgeojson(geom)::json as geom' : ''} from ${params.name.replace(/'/g, '')} limit 10`);

    return {
      count, geom: !!geom, bounds, extent, columns, rows,
    };
  }
  catch (err) {
    return { error: err.toString(), status: 500 };
  }
}