@bazilio-san/af-stream/dist/esm/db/DbBase.js

Data stream from database table

import { DEBUG_SQL } from '../constants';
export class DbBase {
    constructor(options) {
        this.noLock = '';
        this.options = options;
        const { streamConfig, dbConfig } = options;
        let host;
        if (dbConfig.dialect === 'mssql') {
            this.ld = '[';
            this.rd = ']';
            this.recordsetPropName = 'recordset';
            this.noLock = ' WITH(NOLOCK) ';
            host = dbConfig.server;
        }
        else {
            this.ld = '"';
            this.rd = '"';
            this.recordsetPropName = 'rows';
            ({ host } = dbConfig);
        }
        const { ld, rd } = this;
        this.dbInfo = `${dbConfig.user}@${ld}${host}:${dbConfig.port}${rd}.${ld}${dbConfig.database}${rd}`;
        const { fields, src } = streamConfig;
        const { schema, table, tsField, idFields } = src;
        if (Array.isArray(fields)) {
            this.fieldsArray = [...fields];
        }
        else {
            this.fieldsArray = Object.keys(fields);
        }
        this.fieldsList = this.fieldsArray.map((fName) => `${ld}${fName}${rd}`).join(', ');
        this.schemaAndTable = `${ld}${schema}${rd}.${ld}${table}${rd}`;
        this.tsField = tsField;
        this.idFields = idFields;
        this.sortBy = [tsField, ...idFields].map((f) => `${ld}${f}${rd}`).join(',');
    }
    async getPool() {
        return null;
    }
    async close() {
        return true;
    }
    // eslint-disable-next-line @typescript-eslint/no-unused-vars,no-unused-vars
    async query(strSQL) {
        return null;
    }
    async _getColumnsNames() {
        return [];
    }
    async init() {
        const { schemaAndTable, options: { exitOnError, streamConfig: { streamId } }, fieldsArray } = this;
        const columnsNames = await this._getColumnsNames();
        const unknownFields = fieldsArray.filter((name) => !columnsNames.includes(name));
        if (unknownFields.length) {
            exitOnError(`Table ${schemaAndTable} is missing fields specified in the ${streamId} stream configuration:\n\t${unknownFields.join('\n\t')} `);
        }
    }
    // eslint-disable-next-line @typescript-eslint/no-unused-vars, no-unused-vars
    limitIt(strSQL, limit) {
        return strSQL;
    }
    getPortionSQL({ startTs, endTs, limit }) {
        const { tsField, ld, rd, options: { millis2dbFn } } = this;
        let sql = `SELECT ${this.fieldsList}
               FROM ${this.schemaAndTable}
               WHERE ${ld}${tsField}${rd} >= ${millis2dbFn(startTs)}
                 AND ${ld}${tsField}${rd} <= ${millis2dbFn(endTs)}
               ORDER BY ${this.sortBy}`;
        if (limit) {
            sql = this.limitIt(sql, limit);
        }
        return sql;
    }
    async getPortionOfData({ startTs, endTs, limit }) {
        var _a;
        const { options: { eventEmitter, streamConfig: { streamId } }, dbInfo } = this;
        const sql = this.getPortionSQL({ startTs, endTs, limit });
        if (DEBUG_SQL) {
            const payload = { streamId, sql, startTs, endTs, limit, dbInfo };
            eventEmitter.emit('get-portion-of-data-sql', payload);
        }
        const result = await this.query(sql);
        if (DEBUG_SQL) {
            const payload = { streamId, sql, count: (_a = result === null || result === void 0 ? void 0 : result[this.recordsetPropName]) === null || _a === void 0 ? void 0 : _a.length };
            eventEmitter.emit('get-portion-of-data-count', payload);
        }
        return (result === null || result === void 0 ? void 0 : result[this.recordsetPropName]) || [];
    }
}
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