0.0.2 • Published 9 years ago

query_builder v0.0.2

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github
Last release
9 years ago

Nodejs MySQL Query Builder

A small lib that builds query using mysql and nodejs

credits to https://github.com/felixge/node-mysql for mysql nodejs module

Table of Contents

Introduction

This is a small mysql query builder using the nodejs mysql driver by felixge.

Sample Usage:

var query_builder = require('query_builder');

var dbconn_default = {
	host : 'host',
	user : 'user',
	pass : 'password',
	dbase : 'database_schema'
};

var qb = new query_builder( dbconn_default );

var select_details = {
	table : 'table_name',
	fields : [ 'field1', 'field2', ... ],
	conditions : {
		field1 : 'value1',
		field2 : 'value2'
	}
};

qb.select( select_details, function( err, rows ){
	if( err )
		console.log( err );
	else
		console.log( rows );
});

By this, we can generate a query something like this:

SELECT `field1`, `field2` FROM `table_name` WHERE `field1` = 'value1' AND `field2` = 'value2'

Database Configuration and Connecting to your Database

This module used the poolcluster functionality that provides multiple host connection.

Below is how you connect to your default database schema.

var dbconn_default = {
	host : 'host',
	user : 'user',
	pass : 'password',
	dbase : 'database_schema'
};

var default_schema = new query_builder( dbconn_default );

OR

var dbconn_default = {
	host : 'host',
	user : 'user',
	pass : 'password',
	dbase : 'database_schema'
};

var qb = new query_builder();

qb.add( dbconn_default );

Connect in other database

var dbconn1 = {
	host : 'host',
	user : 'user',
	pass : 'password',
	dbase : 'other_database_schema',
	pool_name : 'DBCONN1'
};

qb.add( dbconn1 );

qb.select( 
	{
		table : 'table_name_in_another_database',
		fields : [ 'field1', 'field2', ... ],
		conditions : {
			field1 : 'value1',
			field2 : 'value2'
		},
		pool_name : 'DBCONN1'
	}, 
	function( err, rows ){
		if( err )
			console.log( err );
		else
			console.log( rows );
	}
);

Connection Options

Configuration to establish connection are as follows:

  • host : Hostname of the database.
  • user : The username used to connect to the database.
  • pass : The password used to connect to the database.
  • dbase : The name of the database you want to connect to.
  • pool_name : Connection name identifier ( use when using multiple connections ).

Queries

To submit a query, use the following functions.

qb.select( query_details_here, callback );
qb.update( query_details_here, callback );
qb.delete( query_details_here, callback );
qb.insert( query_details_here, callback );
qb.native_query( query_here, callback );

This will automatically generate, escape and execute a query.

Select Statement

Options for Select Statement

  • table : The table name that you want to select. Required.
  • fields : An array of table fields that you want to show.
  • conditions : This is for WHERE clause. Please see Build a Condition Parameters.
  • joins : This is for JOIN portion of your query. Please see Build a Join Parameters.
  • order : Set an ORDER BY clause.
  • group : Permits you to create a GROUP BY clause.
  • limit : Limit the number of rows you would like returned by the query.
  • start_row : Set a result offset. Commonly used on pagination functionality.
  • count : Determine the number of rows in a particular table. A boolean type. Set to false by default.
  • count_fields : Field set with COUNT option. Sample is COUNT( users.id ) as X. This will overwrite the fields option.
  • show_query : View the generated query. Please see View the Generated Query.
	qb.select(
		{
			table : 'table',
			fields : [ 'field1', 'field2' ],
			conditions : {
				field1 : 'value1',
				field2 : 'value2'
			},
			order : 'field_name ASC',
			group : 'field_name, ...',
			limit : 10,
			start_row : 1,
			show_query : true
		},
		function( err, row ){
			// callback
			// err : an error code, msg
				// { [Error: ER_NO_SUCH_TABLE: Table 'database_schema.table' doesn't exist]
				//  code: 'ER_NO_SUCH_TABLE',
				//  errno: 1146,
				//  sqlState: '42S02',
				//  index: 0 }
			// row : contain results of the query
				// [{
				//	field1 : value1,
				//	field2 : value2
				//	}]
		}
	);

Update Statement

Options for Update Statement

  • table : The table name where you want to update a particular record. Required.
  • details : This is where we set the fields and its new values. Please see build Set Fields Parameters.
  • conditions : This is for WHERE clause. Please see Build a Condition Parameters.
  • show_query : View the generated query. Please see View the Generated Query.
	qb.update(
		{
			table : 'table',
			details : {
				field3 : 'new_value',
				...	   : '...'
			},
			conditions : {
				field1 : 'value1',
				field2 : 'value2'
			},
			show_query : true
		},
		function( err, result, number_of_changed_rows ){
			// callback
			// err : an error code, msg
				// { [Error: ER_NO_SUCH_TABLE: Table 'database_schema.table' doesn't exist]
				//  code: 'ER_NO_SUCH_TABLE',
				//  errno: 1146,
				//  sqlState: '42S02',
				//  index: 0 }
			// result : contain results of the query
			// number of changed rows : The number of changed rows when executing the update statement
		}
	);

Delete Statement

Options for Delete Statement

  • table : The table name where you want to delete a particular record. Required.
  • conditions : This is for WHERE clause. Please see Build a Condition Parameters.
  • show_query : View the generated query. Please see View the Generated Query.
	qb.delete(
		{
			table : 'table',
			conditions : {
				field1 : 'value1',
				field2 : 'value2'
			},
			show_query : true
		},
		function( err, result, number_of_affected_rows ){
			// callback
			// err : an error code, msg
				// { [Error: ER_NO_SUCH_TABLE: Table 'database_schema.table' doesn't exist]
				//  code: 'ER_NO_SUCH_TABLE',
				//  errno: 1146,
				//  sqlState: '42S02',
				//  index: 0 }
			// result : contain results of the query
			// number of affected rows : The number of deleted rows when executing the delete statement
		}
	);

Insert Statement

Options for Insert Statement

  • table : The table name where you want to insert a particular record. Required.
  • details : This is where we set the fields and its values. Please see build Set Fields Parameters.
  • show_query : View the generated query. Please see View the Generated Query.
	qb.insert(
		{
			table : 'table',
			details : {
				field1 : 'value1',
				field2 : 'value2'
			}
		},
		function( err, result, inserted_id ){
			// callback
			// err : an error code, msg
				// { [Error: ER_NO_SUCH_TABLE: Table 'database_schema.table' doesn't exist]
				//  code: 'ER_NO_SUCH_TABLE',
				//  errno: 1146,
				//  sqlState: '42S02',
				//  index: 0 }
			// result : contain results of the query
			// inserted id : The generated primary id of the newly created row
		}
	);

Native Query

Options for executing a query

  • query : Your query statement to execute.
  • pool_name : Use this if you have multiple connections. Optional.
	qb.native_query( { query : 'SELECT * FROM users' }, function( err, result ){
		console.log( result );
	});

Set Field Clause

This is for select and insert queries.

To build on what fields to insert and/or update, please create an object of field names and values

{ field1 : 'value', field2 : 'value' }

This will generate

UPDATE `table` SET `field1` = 'value', `field2` = 'value';
INSERT INTO `table` SET `field1` = 'value', `field2` = 'value';

Build a Condition Clause

This is where we build the WHERE clause.

For simple condition, this will generate an AND operator by default

	{
		field1 : 'value',
		field2 : 'value'
	}
	`field1` = 'value' AND `field2` = 'value'

Joined by OR

	{
		or : {
			field1 : 'value',
			field2 : 'value'
		}
	}
	`field1` = 'value' OR `field2` = 'value'

IN clauses

	{
		field1 : {
			field1 : 'value',
			field2 : 'value'
		}
	}
	`field1` IN( 'value', 'value' )

NOT clauses

	1. {
		not : {
			field1 : 'value',
			field2 : 'value'
		}
	}
	
	2. {
		'field1 !=' : 'value'
	}
	1. `field1` != 'value' AND `field2` != 'value'
	
	2. `field1` != 'value'

LIKE clause, by default, this will joined by AND

	{
		'field1 LIKE' : '%value%',
		'field2 NOT LIKE' : 'value%'
	}
	`field1` LIKE '%value%' AND `field2` NOT LIKE 'value%'

OR LIKE clause

LIKE clause, by default, this will joined by AND

	or : {
		'field1 LIKE' : '%value%',
		'field2 NOT LIKE' : 'value%'
	}
	`field1` LIKE '%value%' OR `field2` NOT LIKE 'value%'

Nested clause

	and : {
		and : {
			key1 : 'value',
			key2 : 'value'
		},
		or : {
			key3 : 'value',
			key4 : 'value'
		},
		not : {
			key5 : 'value',
			key6 : 'value'
		}
	}
	( ( `key1` = 'value' and `key2` = 'value' ) and ( `key3` = 'value' or `key4` = 'value' ) and ( `key5` != 'value' AND `key6` != 'value' ) )

Other operators

	{
		'field1 !=' : 1,
		'field2 <=' : 1,
		'field3 >=' : 1
	}
	field1 != 1 AND field2 <= 1 AND field3 >= 1

Summary of Condition clause

	{
		field1 : 'value',
		field2 : 'value',
		'field1 !=' : 'value',
		'field1 LIKE' : '%value%',
		'field2 NOT LIKE' : 'value%',
		'field1 !=' : 1,
		'field2 <=' : 1,
		'field3 >=' : 1
		or : {
			field1 : 'value',
			field2 : 'value',
			'field1 LIKE' : '%value%',
			'field2 NOT LIKE' : 'value%'
		},
		and : {
			field1 : 'value',
			field2 : 'value'
		},
		field3 : {
			key1 : 'value',
			key2 : 'value'
		},
		not : {
			field1 : 'value',
			field2 : 'value'
		},
		and : {
			and : {
				key1 : 'value',
				key2 : 'value'
			},
			or : {
				key3 : 'value',
				key4 : 'value'
			},
			not : {
				key5 : 'value',
				key6 : 'value'
			}
		}
	}
	SELECT 		* 
	FROM 		`table` 
	WHERE  		`field1` = 'value' 
				AND 
				`field2` = 'value' 
				AND 
				field1 != 1 
				AND 
				field1 LIKE '%value%' 
				AND 
				field2 NOT LIKE 'value%' 
				AND 
				field2 <= 1 
				AND 
				field3 >= 1 
				AND 
				( `field1` = 'value' or `field2` = 'value' or field1 LIKE '%value%' or field2 NOT LIKE 'value%' ) 
				AND 
				( ( `key1` = 'value' and `key2` = 'value' ) and ( `key3` = 'value' or `key4` = 'value' ) and ( `key5` != 'value' AND `key6` != 'value' ) ) 
				AND 
				`field3` IN ( 'value', 'value' )
				AND 
				( `field1` != 'value' AND `field2` != 'value' )
	;

Build a Join Clause

Permits you to write the JOIN portion of your query.

Options are as follows:

  • joins : An object of table details to join.
  • type : Optional and this is JOIN by default. Join types are left, right and inner.
  • ON clause : This is where the ON condition resides. Similar to Condition parameter format.
	qb.select(
		{
			table : 'users',
			joins : {
				'user_types' : {
					type : 'left',
					'users.user_type_id !=' : 'user_types.user_type_id'
				},
				'another table to join' : {
					'field' : 'field'
				}
			}
		},
		function( err, rows ){
			console.log( rows );
		}
	);
	SELECT * FROM `users` LEFT OUTER JOIN `user_types` ON  users.user_type_id != user_types.user_type_id

View the Generated Query

This will log the generated query using console.log().

Setting is as simple as assigning a boolean value to show_query. This is set false by default.