Class PostgresEngine

src/database-engines/postgres-engine.ts:6–185

import { reportError } from "../services/initialization-error-service";

export class PostgresEngine implements DatabaseEngine {
	public connection: knexlib.Knex | null = null;

	constructor(connector: knexlib.Knex) {
		this.connection = connector;
	}

	getType(): KnexClient {
		return 'postgres';
	}

	getConnection(): knexlib.Knex | null {
		return this.connection
	}

	async isOkay(): Promise<boolean> {
		if (!this.connection) return false;

		try {
			await this.connection.raw('SELECT VERSION()');
			return true;
		} catch (error) {
			reportError(`PostgreSQL OK-check error: ${error}`);
			return false;
		}
	}

	async disconnect(): Promise<void> {
		if (this.connection) this.connection.destroy(() => null);
	}

	async getTableCreationSql(table: string): Promise<string> {
		if (!this.connection) {
			throw new Error('Not connected to the database');
		}

		const { schemaName, tableName } = getTableSchema(table);

		const tableCreationSql = await this.connection.raw(`
        SELECT
            'CREATE TABLE ' || quote_ident(table_schema) || '.' || quote_ident(table_name) || ' (' ||
            string_agg(column_name || ' ' ||
                       CASE
                           WHEN data_type = 'character varying' THEN
                               'character varying(' || character_maximum_length || ')'
                           ELSE
                               data_type
                       END, ', ' ORDER BY ordinal_position) ||
            ');' AS create_sql
        FROM
            information_schema.columns
        WHERE
            table_name = ? AND table_schema = ?
        GROUP BY
            table_name, table_schema
    `, [tableName, schemaName]) as any;

		const sql = tableCreationSql.rows[0]?.create_sql || '';