phanx-mysql
MySQL database wrapper that provides async/await promises.
- Typescript source code included
- Insert and Update Helper Methods
- Named Params Query Formatter included
- Promises included for async/await control-flow
- Idle Connection Auto Closer
- No transpiling required (JS code provided)
requirements
- ECMAScript 6 (ES6)
- Node.JS 6.x or later (tested last on 11.4)
install
npm install phanx-mysql
Copy the config.json file into your project source folder, and update with your database connection information.
Basic Example
const PhanxMysql = require("phanx-mysql");
let config = require("./config.json");
PhanxMysql.config = config;
//optional:
PhanxMysql.setAutoCloseMinutes(1);
async function run() {
let db = await PhanxMysql.createAndStart();
let rows = await db.query("select * from test;");
if (db.error)
console.error(db.error);
console.log(rows);
await db.end();
}
run();
Connections
Open connection
let db = new PhanxMysql();
await db.start();
Or use the static helper method:
let db = await PhanxMysql.createAndStart();
Close connection
This will close the connection and return it to the pool.
await db.end();
Important: Remember to close your connections when you are done with them.
Accessing Results
There are many ways of accessing the result sets from your queries.
Standard callback:
await db.query("select * from test;",null, (err, rows, cbResume) => {
console.log(rows);
//optional, to move past await
cbResume();
});
Rows returned from Promise:
let rows = await db.query("select * from test;");
Rows from getter:
await db.query("select * from test;");
for (let row of db.rows) {
console.log(row);
}
Async Looping (non-blocking):
await db.query("select * from test;");
await db.asyncForEach((i,row,cbNext)=> {
console.log(i,row);
cbNext();
});
//done looping
Row stepping:
await db.query("select * from test;");
while (db.hasRows()) {
let row = db.row;
console.log(row);
}
Note: You could use this method in a more asynchronous manner.
Parameters within a Query
The query method's second parameter allows you to pass parameters to your SQL statement as an array of any data-type.
await db.query("select * from test where id=? ;", [55]);
In this example, the value of 55 will be placed where the question mark is, and will be stripped of all SQL injections.
Even for strings you do not include quotes, such as:
await db.query("select * from test where username=? ;", ["Tester"]);
For LIKE searches you would include the wildcard characters in the array, such as:
await db.query("select * from test where username like ? ;", [username+"%"]);
This would look for all records with a username that start with the value that is within the username variable.
You can pass multiple parameters to your query as well, since the parameters is an array, like so:
await db.query("select * from test where username=? and registered=? ;", [username,registered]);
It is important to note the order in which you place the question marks in your SQL, and the order in which you pass the variables within the array.
Best practices with parameters
You should not use question mark parameters for anything other than values that are passed to the database server. In other words, you should not use a question mark in place of a table name or column name. While it may function in the mysql module we are wrapping, it is not how parameterized queries work in most other database engines.
Named Params within a Query
You may now use named params within your queries instead of question marks.
You will first need to enable in your config.json a new property. The example config already has this set to true.
"useNamedParamsQueryFormat":true
Then instead of passing an Array into the query params (the second parameter), you should now pass an object of key/value pairs. Doing so will trigger a new query formatter.
Example:
let results:Array<any> = await db.query(
"select * from users where username=:username and email like :email ;",
{username: "Tester", email: "%@gmail.com"});
In this example the named params ":username" and ":email" will be replaced using the keys in the passed in object. No more question mark params needed! Fancy!
You can, however, always fall back to using question mark params if you pass in an array or a string in as the second parameter in the query method.
Error Handling
throwErrors
By default throwErrors is enabled. This means that you should wrap all your queries with a try/catch block and handle the exceptions this way.
Disable Throwing Errors:
db.throwErrors = false;
If you disable throwing errors you allow yourself to check if there was an error ont he last query by using the error property.
Allowing you to check after every query if there was an error.
if (db.error) {
console.error("Database error: ",db.error);
return;
}
Helper Methods
selectRow
Returns the first row of the array as an Object.
let row = await db.selectRow("select * from test where id=? ;", [5]);
selectArray
Returns the result set as an array of row objects.
let array = await db.selectArray("select * from test where banned=0 ;");
Transaction Methods
Executes the sql statements for transactions.
await db.begin();
await db.commit();
await db.rollback();
Important: Be sure to use a single connection for the entirety of the transaction and for a single transaction at a time.
Row Count
After any query, you may also want to check how many rows were returned before looping.
if (db.rowCount > 0) {
//.. loop
} else {
console.log("No rows found.");
}
Auto Closer
Enabling auto closer in the dbConfig.json file allows database connections that you leave open to be automatically close after a timeout interval provided in minutes.
By default this is not enabled, however you may want to keep this enabled and watch the console to see if the auto closer picks up on any open connections so you can address it and properly close it when you are done.
Insert Helper
Optional helper to assist in inserting simple queries into your database.
3 Ways to do the same thing: Inserts a new row into the "test" table with name provided as "Tester" and the ID left null, so to auto-increment.
await db.insert("test", {name:"Tester"}).finalize();
let insert:PhanxInsert = db.insert("test");
insert.row({name:"Tester"});
await insert.finalize();
await db.insertAndRun("test", {name:"Tester"});
Update Helper
Optional helper to assist in updating simple queries in your database.
3 Ways to do the same thing: Updates the record with ID of 1, setting the name to "Tester" in the "test" table.
await db.update("test", {id:1}, null, {name:"Tester"}).finalize();
let update:PhanxUpdate = db.update("test", "id=?", [1]);
update.row({name:"Tester"});
await update.finalize();
await db.updateAndRun("test", {id:1}, null, {name:"Tester"});
//or
await db.updateAndRun("test", "id=?", [1], {name:"Tester"});
Change Log
0.3.11
- Updated dependency versions.
0.3.10
- Improved debug tracing to not be as noisy.
- Added a new config.json property "showConnectionLeftOpenTrace" to only report when connections are left open. This will be enabled by default.
0.3.9
- Critical Bug Fixed: Memory leak in the unique guid key generator. Keys will no longer remain in memory.
0.3.3
- Fixed bug with insert and update returned results (newly inserted id and rows affected).
0.3.2
- Debug trace messages are now configurable, set config.json: "showDebugTraces".
0.3.1
- Added escape method to assist in escaping strings to be used within queries.
0.3.0
- Query's now support named params in addition to question marks. See Named Params section above.
- Insert helper's run() method now returns the newly inserted row ID.
- Update helper's run() method now returns the number of records affected.
0.2.0
- Insert and Update methods to help write insert and update queries quickly.
- Query now accepts a single value outside of an array.
- Added printQuery method to assist with debugging queries with parameters.
- Improved readme documentation to assist with queries with parameters.