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EMySQL API

Free Pure ECMAScript MySQL API to Download

Pure ECMAScript MySQL Application Programming Interface for Node.js

Foreword: On this page you have the features of the API and code examples on how to use them; you also have the download hyperlink.

By: Chrysanthus Date Published: 28 Jul 2016

EMySQL API for all Operating Systems

EMySQL API stands for ECMAScript MySQL Application Programming Interface. An API is an application or library (module) that facilitates communication between two other applications. This one is free to download. On this page you have the features of the API and code examples on how to use them; you also have the download hyperlink. The library works in all operating systems.

Including
    const mysql = require('./server/Mysql.js');

where Mysql.js is the main module file and it is in the directory, server.

Connection
    var con = new mysql.Connection("user", "secret", "localhost", 3306, function(err)
        {
            if (err)
                console.log(err);
        });

In the API, err is either false, a string or a single element array, whose element is a map with error data.

Query
    var selStr = `SELECT * FROM pet WHERE species = 'snake' OR species = 'bird'`;
    con.query(selStr, function(err, result)
        {
            if (err)
                console.log(err);
            else
                {
                 for (i=0; i<result.length; ++i)
                     {
                            tempStr = `${result[i].get('name')}, ${result[i].get('owner')}, ${result[i].get('species')}, ${result[i].get('sex')}, ${result[i].get('birth')}, ${result[i].get('death')}`
                         console.log(tempStr);
                     }
                }
        });

Note the use of backticks for query string.

Selecting a Database
    var db = "test";
    con.selectDB(db, function(err)
        {
            if (err)
                console.log(err);
        });

Statistics Report
    con.stats(function(err, result)
        {
            if (err)
                console.log(err);
            else
                {
                    console.log(result);
                }
        });

Ping
    con.ping(function(err, result)
        {
            if (err)
                console.log(err);
            else
                {
                    console.log(result);
                }
        });

Closing the Connection
   con.close();

You should close the connection.

Prepared Statements

Prepare and Execute
    var prepareStr = `INSERT INTO pet (name, owner, species, sex, birth, death) VALUES ('Nelly',?,?,'m','2009-03-30',NULL)`;
    con.prepare(prepareStr, function(err, feedback)
        {
            if (err)
                console.log(err);
            else
                console.log('Statement has been prepared');
        });

    var executeStr = `'Marie','wild'`;
    con.execute(executeStr, function(err, feedback)
        {
            if (err)
                console.log(err);
            else
                console.log('Row has been inserted');
        });

    con.statementClose();

Long Cell Values
    var prepareStr = `INSERT INTO pet (name, owner, species, sex, birth, death) VALUES ('Piggy',?,?,'m','2009-03-30',NULL)`;
    con.prepare(prepareStr, function(err, feedback)
        {
            if (err)
                console.log(err);
            else
                console.log('Statement has been prepared');
        });

    con.sendLongData('Likes Pig', 0);
    con.sendLongData('pig\'s long info', 1);

    con.execute(function(err, feedback)
        {
            if (err)
                console.log(err);
            else
                console.log('Row has been inserted');
        });

    con.statementClose();

Do not forget to close the prepared statements (construct) after use.

Multi-Statement
Example of a multi-statement code is:

    var selSt = `SELECT * FROM pet WHERE species = 'snake' OR species = 'bird'; SELECT * FROM pet WHERE death IS NOT NULL`;
    con.query(selSt, function(err, result, field)
        {
            if (err)
                console.log(err);
            else
                {
                    console.log(field);
                    console.log(result);
                }
        });

There are two statements in the code. For the callback function (definition), if the first statement returns an error, then err will be set. Otherwise, result and field will each be a three dimensional structure. The outermost structure is an array. It either leads to a single element array of one map or an array of arrays. Each column index of the outermost structure leads to a result, from one of the multi-statements. If the result is OK, then you have an array of single cell array of one map (OK Map). If the result is an error, then you have an array of single cell array of one map, still (Error Map). If the result is a resultset (set of rows), then you have an array of array of maps, where each row is a map. You should try the above code, to appreciate this. The useful result of a stored procedure is similar in explanation.

For the field, each index of the outermost structure corresponds to an array of array. Each array of array gives the field properties of a resultset.

Stored Procedure
Example of a stored procedure code is:

    var proceduSt = `CREATE PROCEDURE sampleProc (OUT parA DATE)
                        BEGIN
                            SELECT birth
                            FROM pet
                            WHERE name = 'Nelly'
                            INTO parA;
                        END`;
    con.query(proceduSt, function(err, OK)
        {
            if (err)
                console.log(err);
            else
                console.log(OK);
        });

    var setStr = `SET @val = NULL`;
    con.query(setStr, function(err, OK)
        {
            if (err)
                console.log(err);
            else
                console.log(OK);
        });

    var proceduCall = `CALL sampleProc(@val)`;
    con.query(proceduCall, function(err, result)
        {
            if (err)
                console.log(err);
            else
                {
                    console.log(result);
                }
        });

    var selStr = `SELECT @val`;
    con.query(selStr, function(err, result)
        {
            if (err)
                console.log(err);
            else
                {
                    console.log(result);
                }
        });

Transaction
The following is a transaction code:

    var transSt = `START TRANSACTION;
                 SELECT @species := species FROM pet WHERE owner='John';
                 UPDATE pet SET species=@species WHERE owner='Diane';
                 COMMIT;`;
    con.query(transSt, function(err, OK)
        {
            if (err)
                console.log(err);
            else
                {
                    console.log(OK);
                }
        });

Installation
The file to download is a zipped directory. You download it and you unzip it. After unzipping, you will see the file, Mysql.js (plus maybe another file) and the directory, Mysql.

Installation is easy: copy the file, Mysql.js  (plus maybe another file) and the directory, Mysql, to the Node.js server directory in your computer (you should have installed node.js at this point). That is all! Begin to use the API (functions and variables) if you already know how to use it; if you do not already know how to use the API, then visit the site of the link, Using the EMySQL API, below; after which you start using the API. Your Node.js directory can be: c:/server.

Download
Click the following link to download the file, after reading the agreement:

EMySQL API

Discussion Group
The link for discussion is:

Coding by Hand

Related Links

Using the EMySQL API
More Related Links
Node Mailsend
EMySQL API
Node.js Web Development Course
Major in Website Design
Low Level Programming - Writing ECMAScript Module
ECMAScript Course

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