dbq

dbq

dbq = (node-mysql + async for batch execution & flow control) / (a preference for brevity × medium naiveté).

Example: two queries, executed in parallel, two results:

db("select * from ricks order by rickness desc limit 1"
,"select * from mortys where dim=? order by mortyness desc limit 1",["c-137"]
,(rickest,mortyest)=>/*fiddle*/)

Callbacks or Promises

Pass a function as the last input, and that will receive query results as inputs in the order supplied:

db("select * from user where name=?",['morty']
"select name,volume from dims where dim=?",['c-137']
,(morty,dim)=>{/*fiddle*/})

If the last input isn't a function, a promise is returned, so is thenable:

db(  "select * from jerrys where dim=?",["c-137"]
	,"select * from ricks where dim=?",["J19ζ7"]
)	.then(([jerry,doofusRick])=>{//a promise resolves to 1 value, but es6 destructuring can separate them
    	//fiddle
    })
    //if it's thenable, you can catch, too
    .catch(errorHandler)
    //but it's already going to log out when errors happen anyway

Series or Parallel

It can execute queries in series or parallel (assuming you have connection pooling on).

//Parallel looks like this:
db(	//could also have been db.parallel or db.qp or db.q
	 "select * from user"
	,"select * from book"
	,"select * from dinosaur"
).then(([users,books,dinosaurs])=>{/*fiddle*/})

//series would be:
db.qs( //or db.series
	 "update cat set living=false"
    ,"update treaty set active=true where title='Spider Peace'"
    ,"insert into cat2 select * from cat where living=false"
)

node-mysql's ?-substitution syntax is also allowed adjacently, as needed:

db(	 "select * from grandpa where name=?",["rick"]
	,"select * from council"//note no substitution needed here, so no [] is supplied
	,"select * from morty where ?",[{alignment:"evil"}]
	,"select * from dinosaur"
).then(fiddle)

Return Shortcuts

Queries are often performed to retrieve single value results, not arrays of objects.

If you end a query with limit 1, it will take that one result out of its result [], returning just the row {}.

If you also supply only one select clause column, the result will be just that value, not a {key:value}.

Schemize

If your credentials have information_schema access, db.schemize() will query it and put a representation of the database's tables and their columns at db.table for easy referencing elsewhere in code.

Setup & Options

Any key:value passed to the db options object is Object.assigned to db, so will overwrite defaults. Useful to create your own logging. For example, I like to add an ellipsize option to it & the logger so I can see partial or full queries if debugging.

var mysql=require("mysql").createPool({
               host:'x',user:'x',password:'x',database:'x'
              ,useConnectionPooling:true//allow parallel querying!               
              ,connectionLimit:16
              ,connectTimeout:15*60*1000
          })
	,db=require("dbq")(mysql,{//pass in node-mysql initialized above, then an options {}
    	//option:[default]
        ,verbose:true// console.log queries as they happen?
    	,log:(query,rows,queryLine,took,db)=>{//maybe you want to customize how queries are logged
        	console.log(`query in ${took}s:`,query.sql)
        }
    })