sqlbits

2.2.1 • Public • Published

sqlbits

var bits = require('sqlbits'), $=bits.$,SELECT=bits.SELECT,BETWEEN=bits.BETWEEN,AND=bits.AND;
 
var query =
  SELECT('id,first,last,age')
        .FROM('peeps')
        .WHERE("first=",$("Tom"), AND, "age",BETWEEN(18, 25))
        .ORDERBY('last')
 
console.log(query+";");
//SELECT id,first,last,age FROM peeps WHERE(first=$1 AND age BETWEEN $2 AND $3) ORDER BY last;
console.log(query.params);
//[ 'Tom', 18, 25 ]

Installation

$ npm install sqlbits

The "bits"

The project is named Sqlbits because it aims to only provide bits of help with building SQL query strings. You can use a bit to generate pieces of a query or in conjunction with other bits to form a complete query... if that's what raises your flag.

There are 3 types of bits: Contexts, Statements, Params

undefined values

By design, most statements will not output if all associated parameters are undefined. This example omits the first AND statement because the IN Param only has undefined values:

var bits = require('sqlbits'),
    x, y, z;//intentionally undefined
 
with(bits)//GASP! OMG! ..<rant>The Crock can bite me</rant>
 
console.log(
    SQL(  AND("id",IN(x,y,z),  OR,"1=1")  )+""
);
//AND(1=1)

Syntactic Sugar

In computer science, syntactic sugar is syntax within a programming language that is designed to make things easier to read or to express. -Wikipedia

That's all Sqlbits is. No ORM. No database connectivity. Just sugar.

Hopefully you know what SQL injection is. If not, Google it. Sqlbits makes no effort to protect you from writing injectable code. It helps you manage SQL Parameters, but it is up to you to use them properly.

Concatenating strings with parameters isn't hard- but things can get ugly fast. Consider queries that return data based on different WHERE conditions or ORDER BY preferences. This is very common for reports. For example:

"transactions for product $1, purchased between $2 & $3 for user $4"

...but these conditions need to be optional.

Concatenating a query like that (AND keeping track of the params) gets ugly. This is why Sqlbits omits things when their params are undefined. Here is an example that removes a peice of the data each time. Notice how the output changes.

var bits = require('sqlbits');
 
function example(data){ with(bits)
    var query =
        SELECT("*").FROM("sales")
            .WHERE("product=", $(data.product),
            AND, "purchased", BETWEEN(data.start, data.end),
            AND, "userid=", $(data.userid)
        )
        .ORDERBY(data.sortby);
 
    console.log(query+";");
    console.log(query.params);
}
 
example({product:"widget",start:'01/01/2013',end:'02/01/2013',userid:6543,sortby:"purchased"});
//SELECT * FROM sales WHERE(product=$1 AND purchased BETWEEN $2 AND $3 AND userid=$4) ORDER BY purchased;
//[ 'widget', '01/01/2013', '02/01/2013', 6543 ]
 
example({start:'01/01/2013',end:'02/01/2013',userid:6543,sortby:"purchased"});
//SELECT * FROM sales WHERE(purchased BETWEEN $1 AND $2 AND userid=$3) ORDER BY purchased;
//[ '01/01/2013', '02/01/2013', 6543 ]
 
example({end:'02/01/2013',userid:6543,sortby:"purchased"});
//SELECT * FROM sales WHERE(purchased <=$1 AND userid=$2) ORDER BY purchased;
//[ '02/01/2013', 6543 ]
 
example({userid:6543,sortby:"purchased"});
//SELECT * FROM sales WHERE(userid=$1) ORDER BY purchased;
//[ 6543 ]
 
example({});
//SELECT * FROM sales;
//[]

Chaining

As you've probably noticed, Bits are chainable with other bits, but no effort is made to ensure that the chained bits form logical output. For instance:

var bits = require('sqlbits')
    SELECT = bits.SELECT;
 
var query = SELECT("%@!!").ORDERBY('seawead').ON('top of old smokey');
 
console.log(query+";");
//SELECT %@!! ORDER BY seawead ON top of old smoky;

Perhaps in some future world that output will be desired.

_([string | bit] [,string | bit]...) (the underscore function)

There is also a very general purpose function that is available on the context chain: _(). It allows you to directly append to the output. This provides another way to ensure that sqlbits are just helpers that do not restrict you.

var bits = require('sqlbits'), SELECT = bits.SELECT;
 
console.log(
    SELECT('*').FROM("foo")._('LEFT OUTER JOIN bar').ON("foo.id=bar.id")._(';').sql
);
//SELECT * FROM foo LEFT OUTER JOIN bar ON foo.id=bar.id ;

It isn't the most beautiful syntax, but it works.

Contexts

A Context object manages the sql output and the params Array for what you're doing. Statements and Params need a Context to operate.

This project comes with a PostgreSQL context and output generator, PGContext, which inherits from the Context base Object. It was abstracted to allow for the possibility of other output formaters.

All Context objects will have sql and params getters. Context.toString() proxies to the sql getter.

There are several ways to start a context. You can use the SQL, SELECT, INSERT.INTO, DELETE.FROM, and UPDATE functions... or just create one with new PGContext().

SQL([arg][,arg]...)

As mentioned, sqlbits is here to just provide help. The SQL function frees you from needing other bits. Here is an example that uses MSSQL's TOP N statement which Postgres does not have...

var bits = require('sqlbits'), SQL=bits.SQL, $=bits.$, AND=bits.AND, BETWEEN=bits.BETWEEN
= 100;
 
var ctx = new bits.PGContext();
ctx.createParam = function(idx){ return '@p'+idx; };
 
var query = ctx.SQL("SELECT TOP ", $(n), "FROM books WHERE author LIKE 'Tom%'", AND, "rating", BETWEEN(4.4, 5));
 
console.log(query+";");
//SELECT TOP @p1 FROM books WHERE author LIKE 'Tom%' AND rating BETWEEN @p2 AND @p3;
console.log(query.params);
//[ 100, 4.4, 5 ]

Arguments that are strings will output directly; Use caution to prevent SQL injection.

SELECT([columns])

Creates a Context that starts with a SELECT statement. If the columns argument is undefined the SELECT statement will not output.

var bits = require('sqlbits'), SELECT=bits.SELECT;
 
console.log(    SELECT("foo,bar,baz")+""   );
//SELECT foo,bar,baz
 
console.log(    SELECT().FROM("foo")+""   );
//FROM foo

The columns argument is written as-is; using a variable can lead to SQL injection.

UPDATE([table])

Creates a Context that starts with a UPDATE statement. If the table argument is undefined the UPDATE statement will not output.

var bits = require('sqlbits'), UPDATE=bits.UPDATE,
    users;//intentionally undefined
 
console.log(    UPDATE("passwords")+""   );
//UPDATE passwords

The table argument is written as-is; using a variable can lead to SQL injection.

DELETE.FROM(table)

Creates a Context that starts with a DELETE FROM statement. If the table argument is undefined the DELETE FROM statement will not output.

var bits = require('sqlbits'), DELETE=bits.DELETE,
    users;//intentionally undefined
 
console.log(    DELETE.FROM("history")+""   );
//DELETE FROM history
 
console.log(    DELETE.FROM(users).WHERE("something='bad'")+""   );
//WHERE(something='bad')

The table argument is written as-is; using a variable can lead to SQL injection.

INSERT.INTO(table, values)

Creates a Context that starts with a INSERT INTO statement. If the table argument is undefined the INSERT INTO statement will not output.

var bits = require('sqlbits'), INSERT=bits.INSERT, SQL=bits.SQL;
 
console.log(    INSERT.INTO("conversation", {at:"2013-01-23T19:09:27.793Z",text:"hi"})+""   );
//INSERT INTO conversation (at,text) VALUES ($1,$2)

The table argument is written as-is; using a variable can lead to SQL injection.

If you've done batch inserts and dealt with the pain of keeping track of the params, you'll appreciate this...

var ctx = SQL();
for(var i=0;i<5;i++)
    ctx.INSERT.INTO("things", {id:i, created:'1/1/2013'})._(';\n');
 
console.log(ctx.sql);
//INSERT INTO things (id,created) VALUES ($1,$2) ;
//INSERT INTO things (id,created) VALUES ($3,$2) ;
//INSERT INTO things (id,created) VALUES ($4,$2) ;
//INSERT INTO things (id,created) VALUES ($5,$2) ;
//INSERT INTO things (id,created) VALUES ($6,$2) ;
 
console.log(ctx.params);
//[ 0, '1/1/2013', 1, 2, 3, 4 ]

PGContext

var bits = require('sqlbits'), $=bits.$,
    ctx = new bits.PGContext();
 
//You can call toString() on any chain started
//off of ctx to get that portion of the sql output
console.log(  ctx.AND("1=", $(1)).toString()  );
//AND 1=$1
 
console.log(  ctx.AND("2=", $(33)).OR("3=", $(99)).toString()  );
// AND 2=$2 OR 3=$3
 
console.log(  ctx.AND("4=", $(1)).toString()  );
// AND 4=$1
 
//Calling toString() or ctx.sql will return the entire sql string.
console.log(ctx.sql, ctx.params);
//AND 1=$1 AND 2=$2 AND 3=$1 [ 1, 33 ]

Statements

AND/OR/WHERE/ON([expression [,param][,bit] [,bit]...])
AND/OR/WHERE/ON(bit[,bit]...)

These are considered "conditional" statements and internally use the same code. When called directly, they return a Statment object that can be given to a Context or to another conditional Statement.

Calling them from a Context chain will return the chained Context.

var bits = require('sqlbits'), AND=bits.AND,OR=bits.OR,Statement=bits.Statement,SELECT=bits.SELECT,$=bits.$;
 
var stmt = AND("1=1");
console.log(stmt instanceof Statement);
//true
console.log(stmt);
//{ token: 'AND', expression: '1=1' }
 
//pass the OR statement to the AND statement...
console.log(AND("1=1", OR("2=2")));
//[ { token: 'AND', expression: '1=1' }, { token: 'OR', expression: '2=2' }, token: 'AND' ]
 
 
//you'll most likely want to pass it to a Context...
console.log(  SELECT("*").WHERE("1=1", AND("2=2"), OR("3=3"))+""  );
//SELECT * WHERE(1=1 AND 2=2 OR 3=3)
 
//if that's too many parenthesis for your eyes, you can do this...
console.log(  SELECT("*").WHERE("1=1", AND,"2=2", OR,"3=3")+""  );
//                                     ^^^--just pass the function ref
//SELECT * WHERE(1=1 AND 2=2 OR 3=3)

Want more parenthesis? Let's put some around those OR'd statements.

console.log(  SELECT("*").WHERE("1=1", AND,$("2=2", OR,"3=3"))+""  );
//SELECT * WHERE(1=1 AND(2=2 OR 3=3))

As you can see, another use of the $ function allows you to create a parenthesized group.

SET(data)

Produces a comma separated name=Param pairs.

var bits = require('sqlbits'), UPDATE=bits.UPDATE;
 
console.log(    UPDATE("users").SET({first:"Nic",last:"kapke"})+""   );
//UPDATE users SET first=$1,last=$2
 
var data = {};
console.log(    UPDATE("users").SET(data)+""   );
//UPDATE users

FROM(table)

The FROM statement simply writes "FROM table" to the output. If the table argument is not a string the statment will not be included in the output.

var bits = require('sqlbits'), SELECT=bits.SELECT;
 
console.log(    SELECT("*").FROM("books")+""   );
//SELECT * FROM books

The table argument is written as-is; using a variable can lead to SQL injection.

ORDERBY/GROUPBY([string|Param] [,string|Param]...)

Kicks out ORDER BY or GROUP BY statements. If the arguments are undefined, it will not output.

var bits = require('sqlbits'), SQL=bits.SQL, $=bits.$;
 
console.log( SQL().ORDERBY("id")+"" );
//ORDER BY id
 
//FYI: Postgres ignores parameters in ORDER BY and GROUP BY statements
//...maybe this will change in a future version? maybe I'm wrong? (feedback pls)
console.log( SQL().ORDERBY($("id").DESC)+"" );
//ORDER BY $1 DESC

The string arguments are written as-is; using variables can lead to SQL injection.

LIMIT/OFFSET(number)

Whereas most statements will not generate output if their input is undefined, these default to 0. The number argument must be a Number (passes !isNaN(number) check) or it will use 0 to help prevent accidents.

Params

The Param object represents a parameter in a query. When the query is generated, Param objects add their value to the Statement.params Array and add placeholder(s) to the output. The placeholder for Postgres is '$'+(index+1) (e.g. $1, $2...). If you need something else, override the Context.prototype.createParam function.

Params have ASC and DESC getters that will cause them to output ASC/DESC after the Param. Postgres ignores parameters in ORDER BY statements, but it is included so it is available for other DBs.

$(value)

The $ function will produce a Param object if a non-Statement is passed in.

var bits = require('sqlbits'), $=bits.$, Param=bits.Param, SQL=bits.SQL;
 
console.log(  $(1) instanceof Param  );
//true
 
var query = SQL($(9999).DESC);
console.log(  query.sql  );
console.log(  query.params  );
//$1 DESC
//[ 9999 ]

IN(array)
IN([string | Param] [,string | Param]...)

If an Array is used, all items of the array will become Params.

String arguments are written literally.

Duplicates and undefined values are removed. If no values remain, the statement will be omitted. If only 1 value remains, it will output an equals statement (e.g foo=$1).

var bits = require('sqlbits'), SQL=bits.SQL, $=bits.$, IN=bits.IN,
    x,y,z;//intentionally undefined
 
var query = SQL().IN([8,44,21,44,56]);
console.log( query.sql );
console.log( query.params );
//IN($1,$2,$3,$4)
//[ 8, 44, 21, 56 ]
 
var values = [33,33,33,33,33];
console.log( SQL().WHERE("foo", IN(values))+"" );
//WHERE foo=$1
 
console.log( SQL().WHERE("foo", IN(x,y,z))+"" );
//empty string

BETWEEN(min,max)

If min is undefied the output will use greater than or equals syntax. If max is undefied the output will use less than or equals syntax.

var bits = require('sqlbits'), SELECT=bits.SELECT, $=bits.$, BETWEEN=bits.BETWEEN,
    x;//intentionally undefined
 
console.log( SELECT("*").FROM("numbers").WHERE("id", BETWEEN(1,99))+"" );
//SELECT * FROM numbers WHERE id BETWEEN $1 AND $2
 
console.log( SELECT("*").FROM("numbers").WHERE("id", BETWEEN(1,x))+"" );
//SELECT * FROM numbers WHERE id >=$1
 
console.log( SELECT("*").FROM("numbers").WHERE("id", BETWEEN(x,50))+"" );
//SELECT * FROM numbers WHERE id <=$1

Tests

Just run vows in the root of the project...

$ vows

License

The MIT License (MIT) Copyright (c) 2013 William Kapke

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

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