|
| 1 | +# node-pg-native |
| 2 | + |
| 3 | +[](https://travis-ci.org/brianc/node-pg-native) |
| 4 | + |
| 5 | +High performance native bindings between node.js and PostgreSQL via [libpq](https://github.com/brianc/node-libpq) with a simple API. |
| 6 | + |
| 7 | +## install |
| 8 | + |
| 9 | +You need PostgreSQL client libraries & tools installed. An easy way to check is to type `pg_config`. If `pg_config` is in your path, you should be good to go. If it's not in your path you'll need to consult operating specific instructions on how to go about getting it there. |
| 10 | + |
| 11 | +Some ways I've done it in the past: |
| 12 | + |
| 13 | +- On macOS: `brew install libpq` |
| 14 | +- On Ubuntu/Debian: `apt-get install libpq-dev g++ make` |
| 15 | +- On RHEL/CentOS: `yum install postgresql-devel` |
| 16 | +- On Windows: |
| 17 | + 1. Install Visual Studio C++ (successfully built with Express 2010). Express is free. |
| 18 | + 2. Install PostgreSQL (`http://www.postgresql.org/download/windows/`) |
| 19 | + 3. Add your Postgre Installation's `bin` folder to the system path (i.e. `C:\Program Files\PostgreSQL\9.3\bin`). |
| 20 | + 4. Make sure that both `libpq.dll` and `pg_config.exe` are in that folder. |
| 21 | + |
| 22 | +Afterwards `pg_config` should be in your path. Then... |
| 23 | + |
| 24 | +```sh |
| 25 | +$ npm i pg-native |
| 26 | +``` |
| 27 | + |
| 28 | +## use |
| 29 | + |
| 30 | +### async |
| 31 | + |
| 32 | +```js |
| 33 | +var Client = require('pg-native') |
| 34 | + |
| 35 | +var client = new Client(); |
| 36 | +client.connect(function(err) { |
| 37 | + if(err) throw err |
| 38 | + |
| 39 | + //text queries |
| 40 | + client.query('SELECT NOW() AS the_date', function(err, rows) { |
| 41 | + if(err) throw err |
| 42 | + |
| 43 | + console.log(rows[0].the_date) //Tue Sep 16 2014 23:42:39 GMT-0400 (EDT) |
| 44 | + |
| 45 | + //parameterized statements |
| 46 | + client.query('SELECT $1::text as twitter_handle', ['@briancarlson'], function(err, rows) { |
| 47 | + if(err) throw err |
| 48 | + |
| 49 | + console.log(rows[0].twitter_handle) //@briancarlson |
| 50 | + }) |
| 51 | + |
| 52 | + //prepared statements |
| 53 | + client.prepare('get_twitter', 'SELECT $1::text as twitter_handle', 1, function(err) { |
| 54 | + if(err) throw err |
| 55 | + |
| 56 | + //execute the prepared, named statement |
| 57 | + client.execute('get_twitter', ['@briancarlson'], function(err, rows) { |
| 58 | + if(err) throw err |
| 59 | + |
| 60 | + console.log(rows[0].twitter_handle) //@briancarlson |
| 61 | + |
| 62 | + //execute the prepared, named statement again |
| 63 | + client.execute('get_twitter', ['@realcarrotfacts'], function(err, rows) { |
| 64 | + if(err) throw err |
| 65 | + |
| 66 | + console.log(rows[0].twitter_handle) //@realcarrotfacts |
| 67 | + |
| 68 | + client.end(function() { |
| 69 | + console.log('ended') |
| 70 | + }) |
| 71 | + }) |
| 72 | + }) |
| 73 | + }) |
| 74 | + }) |
| 75 | +}) |
| 76 | + |
| 77 | +``` |
| 78 | + |
| 79 | +### sync |
| 80 | + |
| 81 | +Because `pg-native` is bound to [libpq](https://github.com/brianc/node-libpq) it is able to provide _sync_ operations for both connecting and queries. This is a bad idea in _non-blocking systems_ like web servers, but is exteremly convienent in scripts and bootstrapping applications - much the same way `fs.readFileSync` comes in handy. |
| 82 | + |
| 83 | +```js |
| 84 | +var Client = require('pg-native') |
| 85 | + |
| 86 | +var client = new Client() |
| 87 | +client.connectSync() |
| 88 | + |
| 89 | +//text queries |
| 90 | +var rows = client.querySync('SELECT NOW() AS the_date') |
| 91 | +console.log(rows[0].the_date) //Tue Sep 16 2014 23:42:39 GMT-0400 (EDT) |
| 92 | + |
| 93 | +//parameterized queries |
| 94 | +var rows = client.querySync('SELECT $1::text as twitter_handle', ['@briancarlson']) |
| 95 | +console.log(rows[0].twitter_handle) //@briancarlson |
| 96 | + |
| 97 | +//prepared statements |
| 98 | +client.prepareSync('get_twitter', 'SELECT $1::text as twitter_handle', 1) |
| 99 | + |
| 100 | +var rows = client.executeSync('get_twitter', ['@briancarlson']) |
| 101 | +console.log(rows[0].twitter_handle) //@briancarlson |
| 102 | + |
| 103 | +var rows = client.executeSync('get_twitter', ['@realcarrotfacts']) |
| 104 | +console.log(rows[0].twitter_handle) //@realcarrotfacts |
| 105 | +``` |
| 106 | + |
| 107 | +## api |
| 108 | + |
| 109 | +### constructor |
| 110 | + |
| 111 | +- __`constructor Client()`__ |
| 112 | + |
| 113 | +Constructs and returns a new `Client` instance |
| 114 | + |
| 115 | +### async functions |
| 116 | + |
| 117 | +- __`client.connect(<params:string>, callback:function(err:Error))`__ |
| 118 | + |
| 119 | +Connect to a PostgreSQL backend server. |
| 120 | + |
| 121 | +__params__ is _optional_ and is in any format accepted by [libpq](http://www.postgresql.org/docs/9.3/static/libpq-connect.html#LIBPQ-CONNSTRING). The connection string is passed _as is_ to libpq, so any format supported by libpq will be supported here. Likewise, any format _unsupported_ by libpq will not work. If no parameters are supplied libpq will use [environment variables](http://www.postgresql.org/docs/9.3/static/libpq-envars.html) to connect. |
| 122 | + |
| 123 | +Returns an `Error` to the `callback` if the connection was unsuccessful. `callback` is _required_. |
| 124 | + |
| 125 | +##### example |
| 126 | + |
| 127 | +```js |
| 128 | +var client = new Client() |
| 129 | +client.connect(function(err) { |
| 130 | + if(err) throw err |
| 131 | + |
| 132 | + console.log('connected!') |
| 133 | +}) |
| 134 | + |
| 135 | +var client2 = new Client() |
| 136 | +client2.connect('postgresql://user:password@host:5432/database?param=value', function(err) { |
| 137 | + if(err) throw err |
| 138 | + |
| 139 | + console.log('connected with connection string!') |
| 140 | +}) |
| 141 | +``` |
| 142 | + |
| 143 | +- __`client.query(queryText:string, <values:string[]>, callback:Function(err:Error, rows:Object[]))`__ |
| 144 | + |
| 145 | +Execute a query with the text of `queryText` and _optional_ parameters specified in the `values` array. All values are passed to the PostgreSQL backend server and executed as a parameterized statement. The callback is _required_ and is called with an `Error` object in the event of a query error, otherwise it is passed an array of result objects. Each element in this array is a dictionary of results with keys for column names and their values as the values for those columns. |
| 146 | + |
| 147 | +##### example |
| 148 | + |
| 149 | +```js |
| 150 | +var client = new Client() |
| 151 | +client.connect(function(err) { |
| 152 | + if (err) throw err |
| 153 | + |
| 154 | + client.query('SELECT NOW()', function(err, rows) { |
| 155 | + if (err) throw err |
| 156 | + |
| 157 | + console.log(rows) // [{ "now": "Tue Sep 16 2014 23:42:39 GMT-0400 (EDT)" }] |
| 158 | + |
| 159 | + client.query('SELECT $1::text as name', ['Brian'], function(err, rows) { |
| 160 | + if (err) throw err |
| 161 | + |
| 162 | + console.log(rows) // [{ "name": "Brian" }] |
| 163 | + |
| 164 | + client.end() |
| 165 | + }) |
| 166 | + }) |
| 167 | +}) |
| 168 | +``` |
| 169 | + |
| 170 | + |
| 171 | +- __`client.prepare(statementName:string, queryText:string, nParams:int, callback:Function(err:Error))`__ |
| 172 | + |
| 173 | +Prepares a _named statement_ for later execution. You _must_ supply the name of the statement via `statementName`, the command to prepare via `queryText` and the number of parameters in `queryText` via `nParams`. Calls the callback with an `Error` if there was an error. |
| 174 | + |
| 175 | +##### example |
| 176 | + |
| 177 | +```js |
| 178 | +var client = new Client() |
| 179 | +client.connect(function(err) { |
| 180 | + if(err) throw err |
| 181 | + |
| 182 | + client.prepare('prepared_statement', 'SELECT $1::text as name', 1, function(err) { |
| 183 | + if(err) throw err |
| 184 | + |
| 185 | + console.log('statement prepared') |
| 186 | + client.end() |
| 187 | + }) |
| 188 | + |
| 189 | +}) |
| 190 | +``` |
| 191 | + |
| 192 | +- __`client.execute(statementName:string, <values:string[]>, callback:Function(err:err, rows:Object[]))`__ |
| 193 | + |
| 194 | +Executes a previously prepared statement on this client with the name of `statementName`, passing it the optional array of query parameters as a `values` array. The `callback` is mandatory and is called with and `Error` if the execution failed, or with the same array of results as would be passed to the callback of a `client.query` result. |
| 195 | + |
| 196 | +##### example |
| 197 | + |
| 198 | + |
| 199 | +```js |
| 200 | +var client = new Client() |
| 201 | +client.connect(function(err) { |
| 202 | + if(err) throw err |
| 203 | + |
| 204 | + client.prepare('i_like_beans', 'SELECT $1::text as beans', 1, function(err) { |
| 205 | + if(err) throw err |
| 206 | + |
| 207 | + client.execute('i_like_beans', ['Brak'], function(err, rows) { |
| 208 | + if(err) throw err |
| 209 | + |
| 210 | + console.log(rows) // [{ "i_like_beans": "Brak" }] |
| 211 | + client.end() |
| 212 | + }) |
| 213 | + }) |
| 214 | +}) |
| 215 | +``` |
| 216 | + |
| 217 | +- __`client.end(<callback:Function()>`__ |
| 218 | + |
| 219 | +Ends the connection. Calls the _optional_ callback when the connection is terminated. |
| 220 | + |
| 221 | +##### example |
| 222 | + |
| 223 | +```js |
| 224 | +var client = new Client() |
| 225 | +client.connect(function(err) { |
| 226 | + if(err) throw err |
| 227 | + client.end(function() { |
| 228 | + console.log('client ended') // client ended |
| 229 | + }) |
| 230 | +}) |
| 231 | +``` |
| 232 | + |
| 233 | +- __`client.cancel(callback:function(err))`__ |
| 234 | + |
| 235 | +Cancels the active query on the client. Callback receives an error if there was an error _sending_ the cancel request. |
| 236 | + |
| 237 | +##### example |
| 238 | +```js |
| 239 | +var client = new Client() |
| 240 | +client.connectSync() |
| 241 | +//sleep for 100 seconds |
| 242 | +client.query('select pg_sleep(100)', function(err) { |
| 243 | + console.log(err) // [Error: ERROR: canceling statement due to user request] |
| 244 | +}) |
| 245 | +client.cancel(function(err) { |
| 246 | + console.log('cancel dispatched') |
| 247 | +}) |
| 248 | + |
| 249 | +``` |
| 250 | + |
| 251 | +### sync functions |
| 252 | + |
| 253 | +- __`client.connectSync(params:string)`__ |
| 254 | + |
| 255 | +Connect to a PostgreSQL backend server. Params is in any format accepted by [libpq](http://www.postgresql.org/docs/9.3/static/libpq-connect.html#LIBPQ-CONNSTRING). Throws an `Error` if the connection was unsuccessful. |
| 256 | + |
| 257 | +- __`client.querySync(queryText:string, <values:string[]>) -> results:Object[]`__ |
| 258 | + |
| 259 | +Executes a query with a text of `queryText` and optional parameters as `values`. Uses a parameterized query if `values` are supplied. Throws an `Error` if the query fails, otherwise returns an array of results. |
| 260 | + |
| 261 | +- __`client.prepareSync(statementName:string, queryText:string, nParams:int)`__ |
| 262 | + |
| 263 | +Prepares a name statement with name of `statementName` and a query text of `queryText`. You must specify the number of params in the query with the `nParams` argument. Throws an `Error` if the statement is un-preparable, otherwise returns an array of results. |
| 264 | + |
| 265 | +- __`client.executeSync(statementName:string, <values:string[]>) -> results:Object[]`__ |
| 266 | + |
| 267 | +Executes a previously prepared statement on this client with the name of `statementName`, passing it the optional array of query paramters as a `values` array. Throws an `Error` if the execution fails, otherwas returns an array of results. |
| 268 | + |
| 269 | +## testing |
| 270 | + |
| 271 | +```sh |
| 272 | +$ npm test |
| 273 | +``` |
| 274 | + |
| 275 | +To run the tests you need a PostgreSQL backend reachable by typing `psql` with no connection parameters in your terminal. The tests use [environment variables](http://www.postgresql.org/docs/9.3/static/libpq-envars.html) to connect to the backend. |
| 276 | + |
| 277 | +An example of supplying a specific host the tests: |
| 278 | + |
| 279 | +```sh |
| 280 | +$ PGHOST=blabla.mydatabasehost.com npm test |
| 281 | +``` |
| 282 | + |
| 283 | + |
| 284 | +## license |
| 285 | + |
| 286 | +The MIT License (MIT) |
| 287 | + |
| 288 | +Copyright (c) 2014 Brian M. Carlson |
| 289 | + |
| 290 | +Permission is hereby granted, free of charge, to any person obtaining a copy |
| 291 | +of this software and associated documentation files (the "Software"), to deal |
| 292 | +in the Software without restriction, including without limitation the rights |
| 293 | +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 294 | +copies of the Software, and to permit persons to whom the Software is |
| 295 | +furnished to do so, subject to the following conditions: |
| 296 | + |
| 297 | +The above copyright notice and this permission notice shall be included in |
| 298 | +all copies or substantial portions of the Software. |
| 299 | + |
| 300 | +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 301 | +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 302 | +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 303 | +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 304 | +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 305 | +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 306 | +THE SOFTWARE. |
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