@opengis/fastify-table/dist/server/plugins/pg/funcs/getMeta.js

core-plugins

import init from "./init.js";
import getPG from "./getPG.js";
const data = {};
export default async function getMeta(opt, nocache) {
    const pg = opt?.pg || getPG({ name: "client" });
    if (!pg)
        return { error: "pg connection not established", status: 400 };
    // reconnect if at start of process connection was unavailable
    if (!pg.pk || nocache) {
        await init(pg);
    }
    const table1 = opt?.table || opt;
    const table = pg.pk?.[table1] ? table1 : table1?.replace?.(/"/g, "");
    if (pg?.options?.database && data[pg.options.database]?.[table] && !nocache)
        return data[pg.options.database][table];
    if (!pg?.tlist?.includes(table) &&
        !pg?.tlist?.includes(table?.replace?.(/"/g, ""))) {
        return { error: `${table} - not found`, status: 400 };
    }
    const { fields = [] } = await pg.query(`select * from ${table} limit 0`);
    const pks1 = await pg
        .query(`SELECT json_object_agg(c.conrelid::regclass, a.attname) as pks1 
  FROM pg_constraint c 
    left join pg_attribute a on c.conrelid=a.attrelid and a.attnum = c.conkey[1] 
  WHERE c.contype='p'::"char" and c.conrelid::regclass = $1::regclass`, [table])
        .then((el) => el.rows[0].pks1 || {});
    const pk = table.startsWith("public.")
        ? pks1[table.replace("public.", "")]
        : pks1[table];
    const geomColumns = fields.filter((el) => pg.pgType?.[el.dataTypeID] === "geometry");
    const geomAttr = geomColumns.find((el) => el.name === "geom_4326") || geomColumns[0];
    const dbColumns = await pg
        .query(`select json_object_agg(
    attname, 
    json_build_object(
      'title', pg_catalog.col_description(attrelid,attnum)
      /*,'type', atttypid::regtype */
    )
  ) from pg_catalog.pg_attribute a 
  where attrelid=$1::regclass and attnum>0`, [table])
        .then((el) => el.rows?.[0]?.json_object_agg || {});
    fields.forEach((el) => Object.assign(el, { ...(dbColumns[el.name] || {}) }));
    const res = {
        pk,
        columns: fields,
        geom: geomAttr?.name,
        view: ["v", "m"].includes(pg.relkinds?.[table]),
    };
    if (!data[pg.options.database]) {
        data[pg.options.database] = {};
    }
    data[pg.options.database][table] = res;
    return res;
}