InterceptorQueryRunner

A query runner that intercept all the queries and delegate the execution of the queries to the query runner received as second argument in the constructor.

Supported databases

• MariaDB
• MySQL
• Oracle
• PostgreSQL
• SQLite
• SQL Server

Tip

InterceptorQueryRunner supports synchronous query execution. See the Synchronous query runners for more information.

Do not share connections between requests

A ts-sql-query connection object — along with the query runner instances passed to its constructor — represents a dedicated connection to the database.

Therefore, you must not share the same connection object between concurrent HTTP requests. Instead, create a new connection object for each request, along with its own query runners.

Even if the query runner internally uses a connection pool, the ts-sql-query connection still represents a single active connection, acquired from the pool. It must be treated as such and never reused across requests.

Usage Example

import { QueryType } from "ts-sql-query/queryRunners/QueryRunner";
import { InterceptorQueryRunner } from "ts-sql-query/queryRunners/InterceptorQueryRunner";

interface DurationPayload {
    startTime: number
}
class DurationLogginQueryRunner extends InterceptorQueryRunner<DurationPayload> {
    onQuery(queryType: QueryType, query: string, params: any[]): DurationPayload {
        console.log('onQuery', queryType, query, params)
        return { startTime: Date.now() }
    }
    onQueryResult(queryType: QueryType, query: string, params: any[], result: any, payload: DurationPayload): void {
        const duration = Date.now() - payload.startTime
        console.log('onQueryResult', queryType, query, params, result, duration)
    }
    onQueryError(queryType: QueryType, query: string, params: any[], error: any, payload: DurationPayload): void {
        const duration = Date.now() - payload.startTime
        console.log('onQueryError', queryType, query, params, error, duration)
    }
}

async function main() {
    const connection = new DBConnection(new DurationLogginQueryRunner(otherQueryRunner));
    // Do your queries here
    connection // ...
}

API Overview

The InterceptorQueryRunner is an abstract class where you must implement the following functions:

• onQuery: Executed before the query. This function returns the payload data that will be received by the next functions.
• onQueryResult: Executed after the successful execution of the query. Receives as last argument the payload data created by the onQuery method.
• onQueryError: Executed after the query in case of error. Receives as last argument the payload data created by the onQuery method.

This class uses a generic type to define the payload returned by onQuery and later received by onQueryResult and onQueryError.

All these functions receive as argument:

• type: QueryType: type of the query to be executed. The QueryType is defined as:

type QueryType = 'selectOneRow' | 'selectManyRows' | 'selectOneColumnOneRow' | 'selectOneColumnManyRows' |
    'insert' | 'insertReturningLastInsertedId' | 'insertReturningMultipleLastInsertedId' |
    'insertReturningOneRow' | 'insertReturningManyRows' | 'insertReturningOneColumnOneRow' | 'insertReturningOneColumnManyRows' |
    'update' | 'updateReturningOneRow' | 'updateReturningManyRows' | 'updateReturningOneColumnOneRow' | 'updateReturningOneColumnManyRows' |
    'delete' | 'deleteReturningOneRow' | 'deleteReturningManyRows' | 'deleteReturningOneColumnOneRow' | 'deleteReturningOneColumnManyRows' |
    'executeProcedure' | 'executeFunction' | 'beginTransaction' | 'commit' | 'rollback' | 
    'executeDatabaseSchemaModification' | 'executeConnectionConfiguration'

• query: string: the SQL query to be executed. It will be empty for beginTransaction, commit, or rollback.
• params: any[]: parameters received by the query.
• result: any: (only in onQueryResult) result of the execution of the query.
• error: any: (only in onQueryError) error that happens executiong the query.
• payload: PLAYLOAD_TYPE: (only in onQueryResult or onQueryError) payload data created by the onQuery function.

Info

In case the provided query runner doesn't support low-level transaction management, fake beginTransaction, commit, and rollback will be emitted to allow you to identify them.