dl-nosqldb/README.md

DL nosqldb library

# **dl-nosqldb**

The library dl-nosqldb allows to connect with Cassandra database and manage data.<br><br>

### Install

```javascript
npm install dl-nosqldb

const NoSqlDb = require(dl-nosqldb);
```

### API
http://doc.grupa.onet/display/NOS/API+Reference

> This library is compatible with callback and promise invoke. Below there are examples of usage:

#### ➦ **Example of usage with promise **

```javascript
'use strict';

const Nosqldb = require('dl-nosqldb').Nosqldb;

const nosqldb = new Nosqldb(datasource);
let key = [namespaId];
let colValues = {
    name: 'nosql',
    deleted: false
};

nosqldb.insert(table, key, colValues)
    .then((data) => {
        return callback(null, data);
    })
    .catch((err) =>{
        return callback(err);
    });

```

#### ➦ **Example of useage with callback **

```javascript
'use strict';

const Nosqldb = require('dl-nosqldb').Nosqldb;

const nosqldb = new Nosqldb(datasource);
let key = [namespaId];
let colValues = {
    name: 'nosql',
    deleted: false
};

nosqldb.insert(table, key, colValues, {}, callback);

```

### Available methods

#### get (table, key[, options = {}, cb = null]) {
return data by key

###### options:
  * columns
  * consistency

###### example:

```javascript
   nosqldb.get('table_name', ['col_1_value', 'col_1_value'])
```

#### getRange (table, keyPrefix, options = {}, cb = null) 
return data by part of key
###### options:
  * rangeLt
  * rangeLte
  * rangeGt
  * rangeGte
  * columns
  * orderBy
  * limit
  * consistency

###### example:

```javascript
   nosqldb.getRange('table_name', ['col_1_value']')
```

#### multiGet (items, options = {}, cb = null)
return data from many get query, optionaly limitation to the values of defined columns
###### options:
  * consistency

###### example:

```javascript
   nosqldb.multiGet([
        {
            "table": "table_name",
            "key":  ['col_1_value', 'col_2_value']
        },
        {
            "table": "table_name2",
            "key":  ['col_1_value2', 'col_2_value2']
        }
    ]);
```
```javascript
   nosqldb.multiGet([
        {
            "table": "table_name",
            "key":  ['col_1_value', 'col_2_value'],
            "columns": ["col_2", "col_3", "col_4"]
        },
        {
            "table": "table_name2",
            "key":  ['col_1_value2', 'col_2_value2'],
            "columns": ["col_2", "col_3", "col_4"]
        }
    ]);
```

### insert (table, key, columns, options = {}, cb = null)
added new element
###### options:
  * ttl
  * consistency

###### example:

```javascript
   nosqldb.insert("table_name", ['col_1_value', 'col_2_value'], { "col_3": "test", "col_4": "test" });
```
```javascript
   nosqldb.insert("table_name", ['col_1_value', 'col_2_value'], { "col_3": "test", "col_4": "test" }, {"ttl": 200});
```

#### multiInsert (items, options = {}, cb = null) 
added new elements in one query
###### options:
  * consistency

###### example:

```javascript
    nosqldb.multiInsert( [ 
        {
            "table": "table_name",
            "key": ['col_1_value', 'col_2_value'],
            "columns": { "col_3": "test", "col_4": "test" }
        },
        {
            "table": "table_name",
            "key": ['col_1_value2', 'col_2_value2'],
            "columns": { "col_3": "test", "col_4": "test" },
            "ttl": 200
        }
    ]);
```
#### update (table, key, assignments, options = {}, cb = null)
update data by key
###### options:
  * ttl
  * consistency

###### example:

```javascript
   nosqldb.update("table_name", ['col_1_value', 'col_2_value'], { "col_3": [ "=", "testnew"]});
```

### remove (table, key, options = {}, cb = null)
remove data by key
###### options:
  * columns
  * consistency

###### example:

```javascript
   nosqldb.remove("table_name", ['col_1_value', 'col_2_value']);
```

#### batch (operations, options = {}, cb = null)
execute list of operations (insert or remove only)
###### options:
  * consistency

###### example:

```javascript
   nosqldb.batch([
       {
           "name": "insert",
           "params": {
                "table": "table_name",
                "key": ["col_1_value", "col_2_value"],
                "columns": { "col_3": "test", "col_4": "test" },
                "ttl": 200
           }
       },
       {
           "name": "insert",
           "params": {
                "table": "table_name",
                "key": ["col_1_value2", "col_2_value2"],
                "columns": { "col_3": "test", "col_4": "test" }
           }
       },
       {
           "name": "remove
           "params": {
                "table": "table_name",
                "key": ["col_1_value", "col_2_value"]
           }
       }
   ]);
```