accessor_sqlite

Accessor_SQLite 0.2.0

A MySQL database wrapper, provide easy access to database without writing SQL code

Install & Setup

• Install through npm, following command will do that:

   npm install Accessor_SQLite
   
  

• Create a config directory under your application, and create a database.js under that, which may contain like:

   exports.db_path = "path to database";
  

• Now, Accessor_SQLite is ready to use.

Usage

• Require the Accessor module in your script

   var Accessor = require("Accessor");
  

• Place constructor where you need the Accessor. Do not forget to specify your database engine.

   var tester = Accessor("YOUR_TARGET_TABLE", "SQLite");
  

• After initialization, Accessor will try to obtain the schema, and store it to verify column existence while updating or creating.

Methods

accessor.select( {options}, callback(err, data, fields) );

Perform a select query to obtain data, for example:

	// test_table schema: id, name, email

	var tester = Accessor("test_table");
	
	var options = {
		where: [
			["id", ">", 10],
			"AND",
			["email","LIKE","[e-mail]"]
		],
		
		limit: 100,
		offset: 50,
		
		fields: ["name"]
	};
	
	tester.select( options, function(err, data, fields) {
		if(err) {
			throw err;
		}	
		
		return data;
	} );

Currently, {options} has implements following attributes:

• where
• limit
• offset
• fields

Note

Options may omit which retrieve all records, i.e.

	// test_table schema: id, name, email

	var tester = Accessor("test_table");
	
	tester.select( function(err, data, fields) {
		if(err) {
			throw err;
		}	
		
		return data;
	} );

accessor.create( {dataObject}, callback(err, info) );

Insert data record by given dataObject

	// test_table schema: id, name, email

	var tester = Accessor("test_table");
	
	var dataObject = {
		name: "bu",
		email: "[e-mail]",
		nonSchemaColumn: "test"
	};
	
	tester.create( dataObject, function(err, info) {
		if(err) {
			throw err;
		}	
		
		return info.insertId;
	} );

Note

• On above example, we give a non-exist column called "nonSchemaColumn" to Accessor, which may cause hangup if we insert that to sql query.

  Indeed, Accessor will try to check each attribute and ignore them if not exists, and that should print (on console)

    Warning: nonSchemaColumn is not in database schema, and is not inserted into queryset
  

accessor.update( {options}, {updated_dataObject}, callback(err, info) );

Update records filter by option.where with updated_dataObject

	// test_table schema: id, name, email

	var tester = Accessor("test_table");
	
	var dataObject = {
		email: "[e-mail]",
		nonSchemaColumn: "test"
	};
	
	var options = {
		where: [ 
			["name", "=", "bu"] 
		],
	};
	
	tester.update( options, dataObject, function(err, info) {
		if(err) {
			throw err;
		}	
		
		return info.affectedRows;
	} );
	

Note

• On above example, we give a non-exist column called "nonSchemaColumn" to Accessor, which may cause hangup if we update that in sql query.

  Indeed, Accessor will try to check each attribute and ignore them if not exists, and that should print (on console)

    Warning: nonSchemaColumn is not in database schema, and is not inserted into queryset
  

• If options is omitted, it will update all records. (due to no filter)

    // test_table schema: id, name, email
  
    var tester = Accessor("test_table");
    
    var dataObject = {
    	email: "[e-mail]",
    	nonSchemaColumn: "test"
    };
  
    tester.update( {}, dataObject, function(err, info) {
    	if(err) {
    		throw err;
    	}	
    	
    	return info.affectedRows;
    } );
  

accessor.remove( {options}, callback(err, info) );

Remove records filter by options.where

	// test_table schema: id, name, email

	var tester = Accessor("test_table");
	
	var options = {
		where: [ 
			["name", "=", "bu"] 
		],
	};
	
	tester.update( options, function(err, info) {
		if(err) {
			throw err;
		}	
		
		return info.affectedRows;
	} );
	

Note

• If options is omitted, it will remove all records. (due to no filter)

    // test_table schema: id, name, email
  
    var tester = Accessor("test_table");
  
    tester.remove( {}, function(err, info) {
    	if(err) {
    		throw err;
    	}	
    	
    	return info.affectedRows;
    } );
  

Observer

You can register to some methods, that will notify when such things occured. (e.g. UPDATE)

	// following example will register a function that print out trigger event name
	
	var Accessor = require("Accesor");
	
	var Log = Accessor("Log", "MySQL");
	
	// methods can be register are SELECT, CREATE, UPDATE, REMOVE, INIT
	var register_methods = ["SELECT", "DELETE", "CREATE", "INIT", "UPDATE"];
	
	Log.registerObserver(register_methods, function(event){
		console.log(event);
	});
	

LICENSE

Copyright (c) 2012 Buwei Chiu [e-mail]

Licensed under the MIT License