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    @ssense/mysql
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    1.0.4 • Public • Published

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    MySQL Client

    class Connection

    Connection is a helper that makes it easy to access and send queries to a MySQL or MariaDB server. (see examples here)

    Methods

    Method Returns Description
    constructor(options: ConnectionOptions) Connection Creates a new instance of Connection
    query(sql: string, params?: any[]) Promise<any> Sends a query to MySQL server and return a result
    runInTransaction(callback: TransactionFunction) Promise<any> Executes a list of statements in a MySQL transactional way, managing the transaction (begin, commit, rollback) automatically
    runWithLockTables(locks: LockTableOption[], callback: TransactionFunction) Promise<any> Same as runInTransaction() method, except it explicitly locks tables before running the transaction (calling LOCK TABLES instead of START TRANSACTION)
    close() Promise<void> Closes all opened connections to the database and prevent new connections to be created

    Details

    constructor(options: ConnectionOptions)

    Creates a new instance of Connection

    Parameters

    Name Type Required Description
    options ConnectionOptions Yes The parameters used to connect to the MySQL server

    ConnectionOptions properties

    See here for more detail about options properties.

    Name Type Required Description
    host string Yes MySQL server hostname or IP address
    database string Yes Name of database to use
    port number No MySQL port (default: 3306)
    user string No MySQL username (default: null)
    password string No MySQL password (default: null)
    connectionLimit number No Maximum number of parallel connections in internal MySQL connection pool (default: 10)
    timezone string No The timezone configured on the MySQL server. This is used to type cast server date/time values to JavaScript Date object and vice versa. (default: 'local')

    query(sql: string, params?: any[])

    Sends a query to MySQL server and return a result

    Parameters

    Name Type Required Description
    sql string Yes SQL query
    params any[] No SQL query params for a query with parameters (will be protected against SQL injections, see mysql npm module for more detail)

    Return value

    Type Description
    Promise<any> Result of the executed query

    runInTransaction(callback: TransactionFunction)

    Executes a list of statements in a MySQL transactional way, managing the transaction (begin, commit, rollback) automatically

    Parameters

    Name Type Required Description
    callback TransactionFunction Yes Function in which all the MySQL statements can be executed (will be run in a MySQL transaction)

    TransactionFunction definition

    TransactionFunction is a callback function that will be called with a transaction parameter, this transaction exposes a query function, which has the exact same profile as the query function above. You are therefore able to call transaction.query() to send MySQL queries in a transactional context. See examples for more detail.

    Return value

    Type Description
    Promise<any> Result of the executed transaction

    runWithLockTables(locks: LockTableOption[], callback: TransactionFunction)

    Same as runInTransaction() method, except it explicitly locks tables before running the transaction (calling LOCK TABLES instead of START TRANSACTION)

    Parameters

    Name Type Required Description
    locks LockTableOption[] Yes Array of LockTableOption (tables to lock with lock mode)
    callback TransactionFunction Yes Function in which all the MySQL statements can be executed (will be run in a MySQL transaction)

    LockTableOption properties

    Name Type Required Description
    name string Yes Name of the table to lock
    mode 'READ'|'WRITE' Yes Lock mode to use, must be one of 'READ' or 'WRITE'

    TransactionFunction definition

    Definition for TransactionFunction is available in runInTransaction() method above. See examples for more detail.

    Return value

    Type Description
    Promise<any> Result of the executed transaction

    close()

    Closes all opened connections to the database and prevent new connections to be created

    Examples

    Transactional queries using runInTransaction()

    import { Connection } from '@ssense/framework';
    
    // Create connection
    const connection = new Connection({ ...params });
    
    // Run multiple MySQL commands inside a managed transaction
    const result = await connection.runInTransaction(async (transaction) => {
        const users = await transaction.query('SELECT * FROM USERS');
        if (users.length > 0) {
            await transaction.query('UPDATE users set name=.....');
        }
    
        return users[0];
    });
    
    // result will be the object returned by the runInTransaction() method, here users[0]
    // All the MySQL transaction commands (BEGIN, COMMIT or ROLLBACK) are automatically performed, so you just have to focus on your business case.

    Transactional queries using runWithLockTables()

    import { Connection } from '@ssense/framework';
    
    // Create connection
    const connection = new Connection({ ...params });
    
    // Run multiple MySQL commands inside a managed transaction
    const result = await connection.runWithLockTables(
        [
            { name: 'users', mode: 'WRITE' },
            { name: 'accounts', mode: 'WRITE' },
        ],
        async (transaction) => {
            // When reaching this part of the code, both "users" and "accounts" tables will be locked, even if we don't perfom any query on the "accounts" table
            const users = await transaction.query('SELECT * FROM USERS');
            if (users.length > 0) {
                await transaction.query('UPDATE users set name=.....');
            }
    
            return users[0];
        },
    );
    
    // result will be the object returned by the runWithLockTables() method, here users[0]
    // All the MySQL transaction commands (BEGIN, COMMIT or ROLLBACK) are automatically performed, so you just have to focus on your business case.

    Install

    npm i @ssense/mysql

    DownloadsWeekly Downloads

    208

    Version

    1.0.4

    License

    ISC

    Unpacked Size

    22.7 kB

    Total Files

    8

    Last publish

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